Overweight BC patients had elevated Ki-67 with the TT genotype (OR 1.67, 95% CI [0.85–3.28], p = 0.041) and Luminal A with ≤4 gestations (TCTT, OR 2.64, 95% CI [1.13–6.14], p = 0.036). This evidence concerns the gene MKI67 and breast cancer.