diff --git a/Eplant/views/eFP/EFPPreview.tsx b/Eplant/views/eFP/EFPPreview.tsx
index 1bcb18e2..0ec2146c 100644
--- a/Eplant/views/eFP/EFPPreview.tsx
+++ b/Eplant/views/eFP/EFPPreview.tsx
@@ -26,6 +26,7 @@ export type EFPPreviewProps = {
   selected: boolean
   colorMode: 'absolute' | 'relative'
   data: EFPData
+  maskThreshold: number
 } & BoxProps
 export default function EFPPreview({
   gene,
@@ -33,6 +34,7 @@ export default function EFPPreview({
   selected,
   colorMode,
   data,
+  maskThreshold,
   ...boxProps
 }: EFPPreviewProps) {
   const colorModeDeferred = React.useDeferredValue(colorMode)
@@ -54,9 +56,10 @@ export default function EFPPreview({
           state={{
             renderAsThumbnail: true,
             colorMode: colorModeDeferred,
+            maskThreshold: maskThreshold
           }}
           geneticElement={gene}
-          dispatch={() => {}}
+          dispatch={() => { }}
         />
         <div
           style={{
diff --git a/Eplant/views/eFP/Viewer/MaskModal.tsx b/Eplant/views/eFP/Viewer/MaskModal.tsx
new file mode 100644
index 00000000..64300894
--- /dev/null
+++ b/Eplant/views/eFP/Viewer/MaskModal.tsx
@@ -0,0 +1,68 @@
+// Import necessary dependencies from Material-UI
+import React, { useState } from 'react';
+import { Modal, Slider, Typography, Button, useTheme } from '@mui/material';
+import { EFPViewerState } from './types';
+
+// Modal component with a slider
+interface MaskModalProps {
+    state: EFPViewerState
+    onClose: () => void
+    onSubmit: (threshhold: number) => void
+}
+
+const MaskModal = ({ state, onClose, onSubmit }: MaskModalProps) => {
+    const [sliderValue, setSliderValue] = useState<number>(state.maskThreshold);
+    const theme = useTheme()
+    const handleSliderChange = (event: Event, newValue: number | number[]) => {
+        setSliderValue(newValue as number);
+    };
+
+    const handleClose = () => {
+        setSliderValue(state.maskThreshold)
+        onClose();
+    };
+
+    const handleSubmit = () => {
+        onSubmit(sliderValue);
+        onClose();
+    };
+
+    return (
+        <Modal open={state.maskModalVisible} onClose={handleClose}>
+            <div style={{
+                width: 350,
+                height: 200,
+                padding: 20,
+                background: theme.palette.background.paperOverlay,
+                margin: 'auto',
+                marginTop: 100,
+                borderRadius: '8px',
+                display: 'flex',
+                flexDirection: 'column',
+                justifyContent: 'space-between',
+            }}>
+                <Typography variant="body2" gutterBottom>
+                    Mask samples if the expression level is within a given range of their standard deviation.
+                </Typography>
+                <Slider
+                    value={sliderValue}
+                    onChange={handleSliderChange}
+                    valueLabelDisplay="on"
+                    valueLabelFormat={(value) => `${value}%`}
+                    min={0}
+                    max={100}
+                />
+                <div style={{ display: 'flex', justifyContent: 'flex-end' }}>
+                    <Button onClick={handleClose} style={{ marginRight: 8 }}>
+                        Cancel
+                    </Button>
+                    <Button variant="contained" color="inherit" onClick={handleSubmit}>
+                        Mask Thresholds
+                    </Button>
+                </div>
+            </div>
+        </Modal>
+    );
+};
+
+export default MaskModal;
diff --git a/Eplant/views/eFP/Viewer/index.tsx b/Eplant/views/eFP/Viewer/index.tsx
index 53fc54c5..4a81982f 100644
--- a/Eplant/views/eFP/Viewer/index.tsx
+++ b/Eplant/views/eFP/Viewer/index.tsx
@@ -18,6 +18,7 @@ import Legend from './legend'
 import NotSupported from '@eplant/UI/Layout/ViewNotSupported'
 import Dropdown from '@eplant/UI/Dropdown'
 import GeneDistributionChart from './GeneDistributionChart'
+import MaskModal from './MaskModal'
 
 type EFPListProps = {
   geneticElement: GeneticElement
@@ -31,6 +32,7 @@ type EFPListProps = {
   >['dispatch']
   height: number
   colorMode: 'absolute' | 'relative'
+  maskThreshold: number
 }
 
 const EFPListItem = React.memo(
@@ -50,6 +52,7 @@ const EFPListItem = React.memo(
             gene={data.geneticElement}
             selected={data.views[i].id == data.activeView.id}
             view={data.views[i]}
+            maskThreshold={data.maskThreshold}
             onClick={() => {
               startTransition(() => {
                 data.dispatch({ type: 'set-view', id: data.views[i].id })
@@ -116,6 +119,8 @@ export default class EFPViewer
         zoom: 1,
       },
       sortBy: 'name',
+      maskThreshold: 100,
+      maskModalVisible: false,
     }
   }
   constructor(
@@ -126,7 +131,7 @@ export default class EFPViewer
     public icon: () => JSX.Element,
     public description?: string,
     public thumbnail?: string,
-  ) {}
+  ) { }
   getInitialData = async (
     gene: GeneticElement | null,
     loadEvent: (progress: number) => void,
@@ -157,6 +162,7 @@ export default class EFPViewer
       viewData: viewData,
       efps: this.efps,
       colorMode: 'absolute' as const,
+
     }
   }
   reducer = (state: EFPViewerState, action: EFPViewerAction) => {
@@ -192,6 +198,16 @@ export default class EFPViewer
               ? ('relative' as const)
               : ('absolute' as const),
         }
+      case 'toggle-mask-modal':
+        return {
+          ...state,
+          maskModalVisible: state.maskModalVisible ? false : true
+        }
+      case 'set-mask-threshold':
+        return {
+          ...state,
+          maskThreshold: action.threshold
+        }
       default:
         return state
     }
@@ -238,9 +254,10 @@ export default class EFPViewer
           state={{
             colorMode: props.state.colorMode,
             renderAsThumbnail: false,
+            maskThreshold: props.state.maskThreshold
           }}
           geneticElement={props.geneticElement}
-          dispatch={() => {}}
+          dispatch={() => { }}
         />
       )
     }, [
@@ -249,6 +266,7 @@ export default class EFPViewer
       props.dispatch,
       sortedViewData[activeViewIndex],
       props.state.colorMode,
+      props.state.maskThreshold
     ])
     const ref = React.useRef<HTMLDivElement>(null)
     const dimensions = useDimensions(ref)
@@ -289,7 +307,7 @@ export default class EFPViewer
             }}
           >
             {/* Dropdown menus for selecting a view and sort options
-            
+
             //TODO: Make the dropdown menus appear closer to the button, left aligned and with a max height */}
             <Box sx={{ marginBottom: 1 }}>
               <Dropdown
@@ -350,6 +368,7 @@ export default class EFPViewer
               geneticElement={props.geneticElement}
               views={sortedEfps}
               colorMode={props.state.colorMode}
+              maskThreshold={props.state.maskThreshold}
             />
           </Box>
           <Box
@@ -365,6 +384,11 @@ export default class EFPViewer
                     data={{ ...props.activeData.viewData[activeViewIndex] }}
                   />
                 )}
+                <MaskModal
+                  state={props.state}
+                  onClose={() => props.dispatch({ type: 'toggle-mask-modal' })}
+                  onSubmit={(threshold) => props.dispatch({ type: 'set-mask-threshold', threshold: threshold })}
+                />
                 <Legend
                   sx={(theme) => ({
                     position: 'absolute',
@@ -378,6 +402,7 @@ export default class EFPViewer
                   state={{
                     colorMode: props.state.colorMode,
                     renderAsThumbnail: false,
+                    maskThreshold: props.state.maskThreshold
                   }}
                 />
                 <PanZoom
@@ -428,6 +453,10 @@ export default class EFPViewer
       action: { type: 'toggle-color-mode' },
       render: (props) => <>Toggle data mode: {props.state.colorMode}</>,
     },
+    {
+      action: { type: 'toggle-mask-modal' },
+      render: () => <>Mask data</>
+    }
   ]
   header: View<EFPViewerData, EFPViewerState, EFPViewerAction>['header'] = (
     props,
diff --git a/Eplant/views/eFP/Viewer/types.tsx b/Eplant/views/eFP/Viewer/types.tsx
index 895503f8..8e2cb15b 100644
--- a/Eplant/views/eFP/Viewer/types.tsx
+++ b/Eplant/views/eFP/Viewer/types.tsx
@@ -18,6 +18,8 @@ export type EFPViewerState = {
   transform: Transform
   colorMode: ColorMode
   sortBy: EFPViewerSortTypes
+  maskModalVisible: boolean
+  maskThreshold: number
 }
 
 export type EFPViewerAction =
@@ -26,3 +28,5 @@ export type EFPViewerAction =
   | { type: 'set-transform'; transform: Transform }
   | { type: 'toggle-color-mode' }
   | { type: 'sort-by'; by: EFPViewerSortTypes }
+  | { type: 'toggle-mask-modal' }
+  | { type: 'set-mask-threshold'; threshold: number }
diff --git a/Eplant/views/eFP/index.tsx b/Eplant/views/eFP/index.tsx
index a6f0c3e6..c7cc76c5 100644
--- a/Eplant/views/eFP/index.tsx
+++ b/Eplant/views/eFP/index.tsx
@@ -1,6 +1,5 @@
 import GeneticElement from '@eplant/GeneticElement'
 import { CircularProgress, Typography } from '@mui/material'
-import React from 'react'
 import { View, ViewProps } from '@eplant/View'
 import { useEFPSVG, useStyles } from './svg'
 import {
@@ -15,11 +14,13 @@ import {
 import _ from 'lodash'
 import { ViewDataError } from '@eplant/View/viewData'
 import SVGTooltip from './Tooltips/EFPTooltip'
+import React, { useState, useMemo, useEffect, useLayoutEffect } from 'react'
 
 export default class EFP implements View<EFPData, EFPState, EFPAction> {
   getInitialState: () => EFPState = () => ({
     colorMode: 'absolute',
     renderAsThumbnail: false,
+    maskThreshold: 100
   })
   tooltipComponent: (props: {
     el: SVGElement | null
@@ -27,7 +28,7 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
     tissue: EFPTissue
     data: EFPData
     state: EFPState
-  }) => React.JSX.Element
+  }) => JSX.Element
   constructor(
     public name: string,
     public id: EFPId,
@@ -51,9 +52,8 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
     const database = xml.getElementsByTagName('view')[0]?.getAttribute('db')
     let webservice = xml.getElementsByTagName('webservice')[0]?.textContent
     if (!webservice)
-      webservice = `https://bar.utoronto.ca/eplant/cgi-bin/plantefp.cgi?datasource=${
-        database ?? 'atgenexp_plus'
-      }&`
+      webservice = `https://bar.utoronto.ca/eplant/cgi-bin/plantefp.cgi?datasource=${database ?? 'atgenexp_plus'
+        }&`
 
     // Get a list of groups and samples
     const sampleNames: string[] = []
@@ -95,9 +95,9 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
         chunks.map((names) =>
           fetch(
             webservice +
-              `id=${gene.id}&samples=${encodeURIComponent(
-                JSON.stringify(names),
-              )}`,
+            `id=${gene.id}&samples=${encodeURIComponent(
+              JSON.stringify(names),
+            )}`,
           )
             .then((res) => res.json())
             .then(
@@ -176,7 +176,6 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
         showText: !props.state.renderAsThumbnail,
       },
     )
-
     const { svg } = view ?? {}
     const id =
       'svg-container-' +
@@ -184,9 +183,9 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
       '-' +
       (props.geneticElement?.id ?? 'no-gene') +
       '-' +
-      React.useMemo(() => Math.random().toString(16).slice(3), [])
-    const styles = useStyles(id, props.activeData, props.state.colorMode)
-    React.useEffect(() => {
+      useMemo(() => Math.random().toString(16).slice(3), [])
+    const styles = useStyles(id, props.activeData, props.state.colorMode, props.state.maskThreshold)
+    useEffect(() => {
       const el = document.createElement('style')
       el.innerHTML = styles
       document.head.appendChild(el)
@@ -196,7 +195,7 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
     }, [props.activeData.groups, styles])
 
     // Add tooltips to svg
-    const [svgElements, setSvgElements] = React.useState<
+    const [svgElements, setSvgElements] = useState<
       {
         el: SVGElement
         group: EFPGroup
@@ -204,7 +203,7 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
       }[]
     >([])
 
-    const svgDiv = React.useMemo(() => {
+    const svgDiv = useMemo(() => {
       return (
         <div
           style={{
@@ -221,7 +220,7 @@ export default class EFP implements View<EFPData, EFPState, EFPAction> {
       )
     }, [svg, id])
 
-    React.useLayoutEffect(() => {
+    useLayoutEffect(() => {
       const elements = Array.from(
         props.activeData.groups.flatMap((group) =>
           group.tissues.map((t) => ({
diff --git a/Eplant/views/eFP/svg.tsx b/Eplant/views/eFP/svg.tsx
index 4524bb17..437c8c6f 100644
--- a/Eplant/views/eFP/svg.tsx
+++ b/Eplant/views/eFP/svg.tsx
@@ -41,9 +41,9 @@ export const useEFPSVG = (
     if (!cache[view.id]) return { view: null, loading: true }
     const parser = new DOMParser()
     const svg = parser.parseFromString(cache[view.id].svg, 'text/xml')
-    ;['width', 'height', 'x', 'y', 'id'].map((s) =>
-      svg.documentElement.removeAttribute(s),
-    )
+      ;['width', 'height', 'x', 'y', 'id'].map((s) =>
+        svg.documentElement.removeAttribute(s),
+      )
     svg.documentElement.setAttribute('class', 'eFP-svg')
     // Remove styling from all of the text tags
     for (const text of svg.querySelectorAll('text, tspan')) {
@@ -84,14 +84,21 @@ export function getColor(
   control: number,
   theme: Theme,
   colorMode: ColorMode,
+  tissueStd?: number,
+  maskThreshold?: number
 ): string {
   const extremum = Math.max(
     Math.abs(Math.log2(group.min / control)),
     Math.log2(group.max / control),
     1,
   )
+  const masked = maskThreshold && tissueStd ?
+    isNaN(group.std) || (tissueStd >= value * (maskThreshold / 100)) :
+    false
   const norm = Math.log2(value / control) / extremum
-  if (colorMode === 'relative')
+  if (masked) {
+    return (theme.palette.secondary.dark)
+  } else if (colorMode === 'relative')
     return norm < 0
       ? mix(theme.palette.neutral.main, theme.palette.cold.main, Math.abs(norm))
       : mix(theme.palette.neutral.main, theme.palette.hot.main, Math.abs(norm))
@@ -107,22 +114,23 @@ export function useStyles(
   id: string,
   { groups, control }: EFPData,
   colorMode: ColorMode,
+  maskThreshold?: number,
 ) {
   const theme = useTheme()
   const samples = groups
     .flatMap((group) =>
       group.tissues.map(
-        (tissue) =>
-          `
-          #${id} .efp-group-${tissue.id} *, #${id} .efp-group-${
-            tissue.id
+        (tissue) => `
+          #${id} .efp-group-${tissue.id} *, #${id} .efp-group-${tissue.id
           } { fill: ${getColor(
             tissue.mean,
             group,
             control ?? 1,
             theme,
             colorMode,
-          )} !important; }`,
+            tissue.std,
+            maskThreshold,
+          )} !important; }`
       ),
     )
     .join('\n')
diff --git a/Eplant/views/eFP/types.tsx b/Eplant/views/eFP/types.tsx
index 076fbe04..ef9c926c 100644
--- a/Eplant/views/eFP/types.tsx
+++ b/Eplant/views/eFP/types.tsx
@@ -25,6 +25,7 @@ export type ColorMode = 'absolute' | 'relative'
 export type EFPState = {
   colorMode: 'absolute' | 'relative'
   renderAsThumbnail: boolean
+  maskThreshold: number
 }
 
 export type EFPSVG = { svg: string; xml: string; id: EFPId }