In the replication stage of MR, CASP8 continued to show a negative correlation with breast cancer risk (IVW: OR = 0.75, 95% CI: 0.62-0.89, P = 0.001), and DDX58 maintained an inverse association with breast cancer risk (IVW: OR = 0.80, 95% CI: 0.67-0.94, P = 0.007). The gene discussed is CASP8; the disease is breast carcinoma.