The most frequently mutated drivers in colorectal cancer, such as APC, KRAS, TP53 and SOX9, as well as other known drivers including PTEN, EGFR, CCDC6, PCBP1, ATM and CTNNB1, were invariably clonal in cancers, except for one tumour with a subclonal KRAS mutation and another with a subclonal TP53 mutation. This evidence concerns the gene KRAS and cancer.