In a study of 1876 CRC patients, the prevalence of mutations in BRAFV600, TP53, PIK3CA, and other genes differed by sublocation within right- and left-sided tumours.20 The authors concluded that the sigmoid-rectal region of the left side appears unique, and the transverse colon is distinct from other right-sided locations. This evidence concerns the gene PIK3CA and colorectal carcinoma.