GDNF and colorectal carcinoma: However, genetically predicted 1-SD increase in glial cell line-derived neurotrophic factor (GDNF) (OR = 1.11; 95% CI: 1.06–1.17; P = 6.19 × 10-5), and latency-associated peptide transforming growth factor beta 1 (LAP TGF-beta-1) (OR = 1.07; 95% CI: 1.00–1.15; P = 4.80 × 10-2) were related to a higher CRC risk.