Genetically elevated serum MMP-10 level were not causally associated with risk of ER-negative BC (OR = 1.00, 95%CI: 0.95–1.06, P = 0.86), which was supported by the results of the other four datasets (ieu-a-1135: OR = 0.99, 95%CI: 0.93–1.06; P = 0.86; ieu-a-1136: OR = 1.00, 95% CI: 0.89–1.13, P = 1.00; ieu-a-1137: OR = 1.05, 95%CI: 0.93–1.19, P = 0.43; ieu-a-1166: OR = 1.00, 95%CI: 0.89–1.13, P = 0.98) (Table 4). This evidence concerns the gene MMP10 and breast cancer.