Receptor tyrosine kinases (EGFR, HER2, PDGFRa, and FGFR in colorectal, breast, head and neck, gastric cancer, NSCLC, glioblastomas, GISTs, melanoma, etc.), PI3KCA and RAS mutation-mediated PI3K hyperactivity, as well as the loss of PTEN or TSC1/2, leading to mTOR hyperactivity in many cancers. The gene discussed is MTOR; the disease is cancer.