KRAS and metastatic colorectal cancer: In a recent analysis of randomized controlled trials in metastatic colorectal cancer patients, RAS mutation prevalence was found to be 55.9%, with KRAS exon 2 mutations being most common (42.6% prevalence), followed by KRAS exon 4 (6.2%), NRAS exon 3 (4.2%), KRAS exon 3 (3.8%), NRAS exon 2 (2.9%), and NRAS exon 4 (0.3%) mutations [6].