CDKN1A and colorectal carcinoma: These studies have also provided insights into the biology of CRC, highlighting the importance of bone morphogenetic protein signalling pathway genes (BMP2, BMP4, GREM1 and SMAD7) (4,5), candidate genes (CDH1), as well as genes not previously implicated in CRC (POLD3, TERC, CDKN1A, VIT1A and SHROOM2) (6,7).