We observed that the rs9651118 T to C transition was negatively associated with MTHFR expression (Spearman’s rank correlation coefficient rho = −0.078, p = 0.026; Figure 2A), indicating that rs9651118 might be an expression quantitative trait loci for MTHFR. Subsequently, we examined differences in MTHFR gene expression between normal and cancer tissues. This evidence concerns the gene MTHFR and cancer.