BMP4 and colorectal carcinoma: In order to refine the location of CRC-associated functional variation close to the GREM1, BMP4 and BMP2 loci, we genotyped 442 SNPs close to rs4779584, rs4444235 and rs961253 in 4,878 CRC cases and 4,914 controls from the UK2 and Scotland2 sample sets and imputed other SNPs within these regions.