PIK3CA and malignant colon neoplasm: Initially, we examined the effect of a variety of aspirin doses (0, 0.5, 1, 2, 4, 6, 8, 10, and 12 mM) on cell proliferation after exposure to aspirin for 12 to 96 hours in two PIK3CA-mutant (HCT15 and HCT116) and PIK3CA-wild-type (SW480 and SW620) colon cancer cell lines.