Additionally, three interactions between MSH4 Ala97Thr/MLH3 Leu844Pro are associated with an increased risk for breast cancer (AG/AA interaction: adjusted OR = 2.35, 95% CI (1.23-4.49), p = 0.01; GG/AA interaction: adjusted OR = 2.11, 95% CI (1.12-3.98), p = 0.02; and GG/AG: adjusted OR = 1.88, 95% CI (1.12-3.15), p = 0.02). This evidence concerns the gene MSH4 and breast cancer.