KRAS and lung adenocarcinoma: In contrast to KRAS, the incidence of BRAF mutations in human lung adenocarcinoma is relatively low (Naoki et al, 2002), but nearly a half of BRAF mutations in this type of cancer are the most common V600EBRAF mutation (COSMIC: http://cancer.sanger.ac.uk/cancergenome/projects/cosmic/), suggesting that V600EBRAF contributes to lung carcinogenesis in some cases.