The results demonstrated that both polymorphisms are correlated with BC and it can be seen that there is a tendency towards the association between aggressiveness of tumor type and (ER-/PR-), over expression of HER2 neu, tumor size and stage with the mutant allele variants of MTHFR rs1801133 TT and MTHFR rs1801131 CC giving very highly significant values. Here, ESR1 is linked to breast cancer.