PIK3CA and malignant colon neoplasm: OncoCarta assays interrogate 99%, 98%, and 78% of the known colon cancer mutations in BRAF, KRAS, and PIK3CA, respectively, based on a large number of colon cancer samples that have been sequenced in BRAF (n = 4628), KRAS (n = 858) and PIK3CA (n = 247).