CXCL12 and colorectal cancer: To test our hypothesis, we conducted this study in two phases: In phase I, we focused on three HIF-coding genes (HIF1A, HIF1B, and HIF2A) and three genes regulated under the hypoxic conditions (LOX, MIF, and CXCL12) and investigated the relationship of their SNPs (n = 49) with outcomes in a small cohort of colorectal cancer patients (n = 272).