Credibility assessment indicated 18 variants (5.8% of the meta-analysed SNPs) tagging 16 loci (rs36053993 and rs34612342 in MUTYH, rs2066847 in NOD2, rs12953717 and rs4464148 in SMAD7, rs1569686 in DNMT3B, rs2736100 in TERT, rs9858822 in PPAR-gamma, rs1862748 in CDH1, rs7259371 in RHPN2, rs355527 in BMP2, rs1800469 in TGFB1, rs10505477 in 8q24, rs16892766 in 8q23.3, rs3802842 in 11q23.1, rs961253 in 20p12.3, rs10795668 in 10p14, rs4951291 in 1q32.1) had the most credible associations with CRC risk and are therefore referred to as ‘positive’ SNPs (table 1, online supplementary tables 2–4). This evidence concerns the gene TGFB1 and colorectal carcinoma.