MTOR and cancer: To investigate this further, gene set analysis (GSA) was conducted in colon, gastric, esophageal, and pancreatic cancers using the GSCA tool for the following cancer-related pathways: TSC/mTOR, RTK, RAS/MAPK, PI3K/AKT, hormone ER, hormone AR, EMT, DNA damage response, cell cycle, and apoptosis.