MTHFR and colorectal cancer: Another study of 117 advanced colorectal cancer patients receiving FOLFOX demonstrated no impact of MTHFR polymorphisms on toxicity; however, the additive score of MTHFR alleles 677T and 1298C was positively linked to response, with response rates of 37%, 53%, 63%, and 80.0% in patients bearing no, one, two, or three favorable alleles, respectively (p = 0.04) [101].