APC and Familial adenomatous polyposis: Approximately 70–85% of cases (including FAP) of CRC development through the chromosomal instability associated with mutations in the APC gene or loss of the long arm of chromosome 5q (which harbors the APC gene), KRAS oncogene mutations, loss of the long arm of chromosome 18q (genes DCC, SMAD2 and SMAD4) and deletion in the short arm of chromosome 17p, which contains the tumor suppressor gene TP53 [7].