PIK3CA and cancer: Dose-dependent effects of PI3K activation have also been documented in the myriad of cellular studies comparing PIK3CA mutations of different potency (see Table S1 and 11, 12), as well as in mouse models of PIK3CA-driven cancer where tumorigenesis is often only observed upon transgenic overexpression of mutant PIK3CA32, 33, 34, 41, 42, 43, 44, 45, 46, 47, 48, 49.