The association of hormone therapy with impaired gains in lower body strength could be explained by musculoskeletal events (e.g., myalgia, joint stiffness, tingling) in breast cancer patients receiving adjuvant aromatase inhibitors and tamoxifen [40], and the high prevalence of arthralgia during aromatase inhibitor treatment in early breast cancer patients [41,42]. The gene discussed is CYP19A1; the disease is Myalgia.