The PI3K/AKT/mTOR pathway is commonly dysregulated in human cancer, due to mutation of dominantly acting oncogenes (PIK3CA, AKT isoforms, MTOR), inactivation of tumor suppressor genes (PTEN, TSC1, TSC2, PIK3R1), and amplification of growth-promoting oncogenes (18). Here, TSC2 is linked to cancer.