Conversely, cytochrome c oxidase subunit 8A was associated with breast cancer as a protective factor (IVW, p=0.059, OR = 0.963, 95% CI: 0.928–0.990) and ADP-ribose pyrophosphatase exhibited a causal association as a protective factor against breast cancer (IVW, p=0.011, OR = 0.962, 95% CI: 0.930–0.997). This evidence concerns the gene COX8A and breast cancer.