Some genes, for example tumor protein p53 (TP53/p53), phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA), and retinoblastoma 1 (RB1), are frequently mutated in a number of cancers and are key genes contributing to tumorigenesis151, 152, 153. This evidence concerns the gene PIK3CA and cancer.