They are V600 in Serine/threonine-protein kinase B-Raf (encoded by BRAF), and R88 and C420 in the phosphatidylinositol-4,5-bisphosphate 3-kinase encoded by PIK3CA. We found both C420 and R88 to be positions of mutational hotspots in endometrium, colon and breast cancer. The gene discussed is PIK3CA; the disease is breast carcinoma.