Based on the coefficients derived from LASSO analysis, a risk score for each patient with BC was calculated using the following formula: risk score = CETP × (5.08 × 10−1) + CLEC11A × (1.10 × 10−1) + CYP2A6 × (7.77 × 10−2) + CYP2A7 × (5.14 × 10−2) + GZMB × (−1.74 × 10−1) + HGF × (3.49 × 10−1) + LDHC × (−3.03 × 10−1) + PLAU × (9.80 × 10−2). This evidence concerns the gene CYP2A6 and breast cancer.