TP53 and colorectal carcinoma: The p53 mutations are often detected in mucosa that is even nondysplastic [98, 99], but APC mutations are present at the late stage of CAC [100–103]. K-ras mutation plays a rare role in CAC development [104], but DNA methylation is an early event in UC [105], although less common than in sporadic CRC [106, 107].