In the TCGA primary tumor samples, pancreas adenocarcinoma (PAAD) is the most KRAS mutant cancer type (somatic mutation frequency 90.6% of 149 cases), followed by colorectal adenocarcinoma (COAD, 42.5% of 220 cases) and lung adenocarcinoma (LUAD, 32.6% of 230 cases) (Figure 1(a)). Here, KRAS is linked to lung adenocarcinoma.