anchor.diff:          } else if(cancerStudy.hasMutationData()) {
               cancerStudiesWithMutations.add(cancerStudy);
           } else {
  -            cancerStudiesWithOutMutations.add(cancerStudy);
  +            // If user wants to get only the mutation data
  +            // don't even add these studies to the list since they don't have any
  +            if(!onlyMutationData) {
  +                cancerStudiesWithOutMutations.add(cancerStudy);
  +            } else {
  +                skippedCancerStudies++;
  +            }
           }
       }
   
  
positive.code:                         <option value="3">Show number of altered cases (studies with mutation data)</option>
                          <option value="4">Show number of altered cases (studies without mutation data)</option>
                          <%
                              } else {
  
                          %>
                          <option value="1">Show percent of altered cases</option>
                          <option value="3">Show number of altered cases</option>
  
negative.code:     // Divide histograms only if we are interested in mutations
      boolean divideHistograms = (dataPriority != 2);
  
      // Check if we wanna show only the mutation data
      boolean onlyMutationData = (dataPriority == 1);
  
      int skippedCancerStudies = 0;
      // Now pool the cancer studies
      ArrayList<CancerStudy> cancerStudiesWithMutations = new ArrayList<CancerStudy>(),
                             cancerStudiesWithOutMutations = new ArrayList<CancerStudy>();
  