KRAS and colonic neoplasm: Talking about pathogenic mutations, only KRAS and PIK3CA showed statistical differences (Supplementary Table 1): KRAS appeared scarcely in left colon cancer (29%), while right colon and rectum showed more than 70% and 60%, respectively; and PIK3CA showed a decreasing progression from right colon to rectum (33%, 14% and 9%)(Figures 1 and 2).