The MTHFR C677T mutation is not a risk factor recognized for HBV-related HCC in a population with a high prevalence of this genetic marker

•MTHFR 677TT may confer a protective effect in HBV-HCC patients in a population with high prevalence of this allele.•Using self-limited subjects as reference, we further confirm the protective effect of MTHFR 677TT on liver disease.•The MTHFR 677TT genotype and T allele are relatively prevalent in the Tianjin population.