 
   configureTile: (outcome, tile) ->
     # Formatting functions.
-    asPct = (val) ->
+    addPctSign = (val) ->
       # Display with a % sign following the value unless it is null.
       result = if val then val.toString().concat('%') else val
     asReactionScore = (val) ->
-      # Display with a + sign following the value if it is not zero.
+      # Display with a + sign following the value if it is not zero or null.
       result = if val > 0 then val.toString().concat('+') else val
     # The tile specification.
     tiles =

            }
            {
              label: 'Intensity'
              accessor: (outcome) -> val = asPct(outcome.estrogen.intensity)
            }
            {
              label: 'Quick Score'

            }
            {
              label: 'Ki-67'
              accessor: (outcome) -> addPctSign(outcome.ki_67)
            }
          ]
    # Return the rows for the designated tile.
