In the reverse MR study, ER+ BC tended to exhibit elevated levels of FGF7 (OR 1.072, 95% CI: 1.004–1.144, P = .037) and decreased levels of FGFR2 (OR 0.930, 95% CI: 0.872–0.992, P = .027). Here, FGF7 is linked to breast cancer.