However, for breast cancer patients with AI-related MS-AEs, the level of RANKL (698.0 ± 62.6 pg/ml) and the ratio of RANKL/OPG (2.43 ± 0.22) were higher than the controls (RANKL: 502.1 ± 45.2 pg/ml, RANKL/OPG: 1.48 ± 0.14, p < 0.05). This evidence concerns the gene TNFSF11 and breast cancer.