RNF43 and adenoma: Notably, RNF43 mutations in sessile adenomas and serrated pathway‐type CRC were associated with the BRAFV600E mutation and CpG island methylator phenotype (CIMP), leading to the methylation of the MLH1 promoter, which further causes microsatellite instability (MSI) without DNA mismatch repair gene mutations [4, 10, 11, 12, 13, 14, 15].