diff --git a/client/src/components/brushableHistogram/index.js b/client/src/components/brushableHistogram/index.js
index 9f501ce9..72642b54 100644
--- a/client/src/components/brushableHistogram/index.js
+++ b/client/src/components/brushableHistogram/index.js
@@ -184,8 +184,21 @@ class HistogramBrush extends React.Component {
     }
   }
 
+  removeHistogram() {
+    const { dispatch, field, colorAccessor } = this.props;
+    dispatch({
+      type: "clear user defined gene",
+      data: field
+    });
+    if (field === colorAccessor) {
+      dispatch({
+        type: "reset colorscale"
+      });
+    }
+  }
+
   render() {
-    const { field, ranges, colorAccessor } = this.props;
+    const { field, ranges, colorAccessor, isUserDefined } = this.props;
 
     return (
       <div
@@ -195,7 +208,22 @@ class HistogramBrush extends React.Component {
         }}
         id={`histogram_${field}`}
       >
-        <p style={{ fontSize: globals.tiniestFontSize }}> {field} </p>
+        <div>
+          <span style={{ fontSize: globals.tiniestFontSize }}> {field} </span>
+          {isUserDefined ? (
+            <span
+              onClick={this.removeHistogram.bind(this)}
+              style={{
+                fontSize: globals.tiniestFontSize,
+                color: globals.blue,
+                cursor: "pointer",
+                marginLeft: 7
+              }}
+            >
+              remove
+            </span>
+          ) : null}
+        </div>
         <svg
           width={this.width}
           height={this.height}
diff --git a/client/src/components/continuous/continuous.js b/client/src/components/continuous/continuous.js
index 32d315d9..78976616 100644
--- a/client/src/components/continuous/continuous.js
+++ b/client/src/components/continuous/continuous.js
@@ -13,16 +13,17 @@ import HistogramBrush from "../brushableHistogram/";
     metadata: _.get(state.controls.world, "obsAnnotations", null),
     colorAccessor: state.controls.colorAccessor,
     colorScale: state.controls.colorScale,
-    selectionUpdate: _.get(state.controls, "crossfilter.updateTime", null)
+    selectionUpdate: _.get(state.controls, "crossfilter.updateTime", null),
+    schema: _.get(state.controls.world, "schema", null)
   };
 })
 class Continuous extends React.Component {
-  handleBrushAction(selection) {
-    const { dispatch } = this.props;
-    dispatch({
-      type: "continuous selection using parallel coords brushing",
-      data: selection
-    });
+  constructor(props) {
+    super(props);
+    this.hasContinuous = false;
+    this.continuousChecked = false;
+
+    this.state = {};
   }
 
   handleColorAction(key) {
@@ -36,11 +37,20 @@ class Continuous extends React.Component {
     };
   }
 
+  componentDidUpdate() {}
+
   render() {
-    const { ranges, obsAnnotations } = this.props;
+    const { ranges, obsAnnotations, schema } = this.props;
+    if (schema && !this.continuousChecked) {
+      this.hasContinuous = _.some(schema.annotations.obs, d => {
+        return d.type === "int32" || d.type === "float32";
+      });
+      this.continuousChecked = true; /* only do this once */
+    }
 
     return (
       <div>
+        {this.hasContinuous ? <p> Continuous metadata </p> : null}
         {_.map(ranges, (value, key) => {
           const isColorField = key.includes("color") || key.includes("Color");
           if (value.range && key !== "name" && !isColorField) {
diff --git a/client/src/components/expression/cellSetButtons.js b/client/src/components/expression/cellSetButtons.js
index 8ccd1ea4..ac4364ea 100644
--- a/client/src/components/expression/cellSetButtons.js
+++ b/client/src/components/expression/cellSetButtons.js
@@ -9,17 +9,23 @@ import actions from "../../actions";
 @connect()
 class CellSetButton extends React.Component {
   set() {
+    const { differential } = this.props;
+
     const set = _.map(this.props.crossfilter.allFiltered(), "name");
 
-    this.props.dispatch({
-      type:
-        "store current cell selection as differential set " +
-        this.props.eitherCellSetOneOrTwo,
-      data: set
-    });
+    if (!differential.diffExp) {
+      /* diffexp needs to be cleared before we store a new set */
+      this.props.dispatch({
+        type:
+          "store current cell selection as differential set " +
+          this.props.eitherCellSetOneOrTwo,
+        data: set
+      });
+    }
   }
 
   render() {
+    const { differential } = this.props;
     return (
       <span style={{ marginRight: 10 }}>
         <button
@@ -28,7 +34,9 @@ class CellSetButton extends React.Component {
             borderRadius: 2,
             padding: "0px 10px",
             height: 30,
-            backgroundColor: globals.brightBlue,
+            backgroundColor: !differential.diffExp
+              ? globals.brightBlue
+              : globals.lightGrey,
             border: "none",
             cursor: "pointer"
           }}
@@ -47,7 +55,7 @@ class CellSetButton extends React.Component {
               top: 0
             }}
           >
-            {this.props.differential[
+            {differential[
               "celllist" + this.props.eitherCellSetOneOrTwo
             ]
               ? this.props.differential[
diff --git a/client/src/components/geneExpression/index.js b/client/src/components/geneExpression/index.js
index 9369b210..54d2664e 100644
--- a/client/src/components/geneExpression/index.js
+++ b/client/src/components/geneExpression/index.js
@@ -36,19 +36,43 @@ class GeneExpression extends React.Component {
       ctx: null,
       axes: null,
       dimensions: null,
-      gene: null
+      gene: ""
     };
   }
+  keyPress(e) {
+    if (e.keyCode == 13) {
+      this.handleClick();
+    }
+  }
+  handleClick() {
+    const { world, dispatch, userDefinedGenes } = this.props;
 
+    if (userDefinedGenes.indexOf(this.state.gene) !== -1) {
+      console.log("That gene already exists");
+    } else if (userDefinedGenes.length > 15) {
+      console.log(
+        "That's too many genes, you can have at most 15 user defined genes"
+      );
+    } else {
+      dispatch(actions.requestGeneExpressionCountsPOST([this.state.gene]));
+      dispatch({
+        type: "user defined gene",
+        data: this.state.gene
+      });
+      this.setState({ gene: "" });
+    }
+  }
   render() {
     const { world, userDefinedGenes } = this.props;
     return (
       <div>
         <input
+          onKeyDown={this.keyPress.bind(this)}
           onChange={e => {
             this.setState({ gene: e.target.value });
           }}
           type="text"
+          value={this.state.gene}
         />
         <button
           style={{
@@ -59,23 +83,7 @@ class GeneExpression extends React.Component {
             marginTop: 20,
             padding: 0
           }}
-          onClick={() => {
-            if (userDefinedGenes.indexOf(this.state.gene) !== -1) {
-              console.log("That gene already exists");
-            } else if (userDefinedGenes.length > 15) {
-              console.log(
-                "That's too many genes, you can have at most 15 user defined genes"
-              );
-            } else {
-              this.props.dispatch(
-                actions.requestGeneExpressionCountsPOST([this.state.gene])
-              );
-              this.props.dispatch({
-                type: "user defined gene",
-                data: this.state.gene
-              });
-            }
-          }}
+          onClick={this.handleClick.bind(this)}
         >
           <CirclePlus
             style={{
@@ -101,7 +109,7 @@ class GeneExpression extends React.Component {
                     key={geneName}
                     field={geneName}
                     ranges={d3.extent(values)}
-                    isUserSelected
+                    isUserDefined
                   />
                 );
               }
diff --git a/client/src/reducers/controls.js b/client/src/reducers/controls.js
index 3f084407..813e5e3c 100644
--- a/client/src/reducers/controls.js
+++ b/client/src/reducers/controls.js
@@ -185,15 +185,35 @@ const Controls = (
           varDataCache: worldVarDataCache
         }
       };
-    case "user defined gene":
+    case "user defined gene": {
       const newUserDefinedGenes = state.userDefinedGenes.slice();
       newUserDefinedGenes.push(action.data);
       return {
         ...state,
         userDefinedGenes: newUserDefinedGenes
       };
-    case "clear user defined gene":
-
+    }
+    case "clear user defined gene": {
+      const { userDefinedGenes } = state;
+      const newUserDefinedGenes = _.filter(userDefinedGenes, d => {
+        return d !== action.data;
+      });
+      return {
+        ...state,
+        userDefinedGenes: newUserDefinedGenes
+      };
+    }
+    case "reset colorscale": {
+      const { world } = state;
+      const colorName = new Array(world.nObs).fill(globals.defaultCellColor);
+      const colorRGB = _.map(colorName, c => parseRGB(c));
+      return {
+        ...state,
+        colorName,
+        colorRGB,
+        colorAccessor: null
+      };
+    }
     case "expression load error":
     case "initial data load error": {
       return {