MTHFR and hepatotoxicity: Summarily, the MTX-related high-level liver toxicity (grade 3–4) was significantly associated with MTHFR rs1801133 polymorphism under allele contrast (T vs. C: OR=1.61, 95%CI=1.07-2.42, P=0.024), homozygote comparison (TT vs. CC: OR=2.11, 95%CI=1.06-4.21, P=0.011), and dominant genetic model (TT/TC vs. CC: OR=3.15, 95%CI=1.30-7.60, P=0.035) in the Asian population but not in the overall population (Figure 2).