CDKN2A and colorectal carcinoma: Various genes including hMLH1, CDKN2A (p16), HLTF, ALX4, TMEFF2, NGFR, NEUROG1, SFRP2 and RUNX3 have emerged as potential blood-based methylation markers for CRC with sensitivities ranging from 34% to 90% and specificities spanning from 69% to 100% [76,77,78,79,80,81,82,83,84,85,86].