private void handleShowExon(Tuple request) {
    SearchService searchService = ServiceLocator.instance().getSearchService();

    Integer exonId = request.getInt("exon_id");

    this.getModel().setExonDTO(searchService.findExonById(exonId));

    if (this.getModel().getQueryParametersVO().getShowMutations()) {
      this.getModel().setMutationSummaryDTOList(searchService.findMutationsByExonId(exonId));
      ((HttpServletRequestTuple) request)
          .getRequest()
          .setAttribute("mutationSummaryDTOList", this.getModel().getMutationSummaryDTOList());
      this.getModel().setRawOutput(this.include(request, this.getModel().getMutationPager()));
    }
    this.getModel().setHeader("");

    this.getModel().getMbrowse().setExonDTO(this.getModel().getExonDTO());
    this.getModel()
        .getMbrowse()
        .setMutationSummaryDTOList(this.getModel().getMutationSummaryDTOList());

    this.setView(new FreemarkerView("exon.ftl", getModel()));
  }