Figure 1: Regions of interest. (a) Tumor (left) and contralateral normal (right) biopsies were collected at the time of surgery. Three regions of interest corresponding to the tumor (red), adjacent normal epithelium (green), and contralateral normal epithelium (blue) were outlined by the study pathologist and used for analysis. (b) Close-up of each region of interest stained with H&E (left) or Feulgen-thionin (right).