anchor.diff:      ArrayList<CancerStudy> cancerStudies = (ArrayList<CancerStudy>)
               request.getAttribute(QueryBuilder.CANCER_TYPES_INTERNAL);
   
  +    // Get priority settings
  +    Integer dataPriority;
  +    try {
  +        dataPriority
  +                = Integer.parseInt(request.getParameter(QueryBuilder.DATA_PRIORITY).trim());
  +    } catch (NumberFormatException e) {
  +        dataPriority = 0;
  +    }
  +
  +    // 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>();
       for(CancerStudy cancerStudy: cancerStudies) {
  -        if(cancerStudy.hasMutationData()) {
  +        if(!divideHistograms) {
  +          // A dirty maneuver to show all studies within a single histogram
  +          cancerStudiesWithMutations.add(cancerStudy);
  +        } 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:             histogramChart2.draw(histogramView2, options2);
  
              var options3 = {
                title: 'Number of Altered Cases for Each Cancer Study with Mutation data (' + genesQueried + ')',
                colors: multipleGenes ? ['#aaaaaa', '#eeeeee'] : ['#aaaaaa',  '#008000', '#002efa', '#ff2617', '#eeeeee'],
                legend: {
                  position: 'bottom'
  
negative.code:            }
  
             var options = {
                title: divideHistograms ? 'Percent Sample Alteration for Each Cancer Study with Mutation Data (' + genesQueried + ')' : 'Percent Sample Alteration for Each Cancer Study (' + genesQueried + ')',
                colors: ['#aaaaaa', '#008000', '#002efa', '#ff2617'],
                legend: {
                  position: 'bottom'
  