For example, the AMPK activator metformin has shown potential for combined application with chemotherapy or immunotherapy in clinical trials of breast cancer, colorectal cancer, and head and neck cancer; while mTOR inhibitors such as everolimus and rapamycin have been widely tested in clinical trials of multiple cancers, including breast cancer, colorectal cancer, liver cancer, and prostate cancer. This evidence concerns the gene MTOR and colorectal cancer.