BMP4 and colorectal carcinoma: Genome-wide association studies have identified mutations in other members of the BMP signaling pathway that are associated with an increased risk of CRC, including BMP2, BMP4, GREM1, and SMAD7 (Broderick et al. 2007; Houlston et al. 2008), which can disrupt normal BMP signaling in the intestinal mucosa.