The association of IFN-γ rs2069705 with the risk of breast cancer was not significant among all participants, while the CT/TT genotypes were significantly related to an elevated risk of breast cancer [1.32 (1.03-1.70)] among the women with <1 fever per year and to a reduced risk of breast cancer [0.63 (0.40-0.99)] among women with ≥1 fever per year compared to the CC genotype.