KRAS and cancer: In our study, there were 32 recurrent altered genes, including conventional cancer genes such as APC (67%), TP53 (53%) and KRAS (27%) (Figure 2C).The most common types of base conversion in the exomic region were C > T transition (26%) in eight alteration categories (Figure 2D), which is consistent with spontaneous cytosine deamination30 being a major mutagenic process in CRCLMs.