KRAS and colorectal carcinoma: Whereas BRAF mutations occurred at a rate similar to what has been reported previously in CRC patients (11.5 vs 10.0% mutated), we found slightly less mutations in NRAS (1.9% vs 6% mutated), and a markedly increased KRAS mutation frequency in the peritoneal metastasis cohort (61.5% vs 35.0% mutated, P = 0.0002) (Fig. 1f and Supplementary Data 4).