PIK3CA and gastric cancer: These include well recognized relationships such as KRAS in pancreatic and colorectal cancers (P = 1.969e-10 and 2.180e-2 respectively), CDK4 in luminal/ER+ breast cancer (P = 3.968e-7 and 9.044e-4 respectively), BRAF in skin cancer (P = 3.109e-3), PIK3CA in breast and gastric cancers (P = 1.343e-4 and 1.689e-3 respectively) and APC in colorectal cancer (P = 2.581e-4), as well as mechanistically supported relationships like CDK2 in ovarian cancer (P = 6.149e-03; Table 2) where CCNE1, the cyclin that interacts with CDK2, is frequently amplified [28, 29].