Currently using a third-generation aromatase inhibitor (anastrozole, letrozole, or exemestane) and self-reported ongoing musculoskeletal symptoms (arthralgia and/or stiffness and/or swelling in one or more joints, bone pain, myalgia, carpal tunnel syndrome, trigger finger), which started or worsened after initiation of aromatase inhibitor therapy and has continued for more than 1 month, and who had a baseline worst pain score over the past week on the Brief Pain Inventory-Short Form ≥3 points on a scale of 0 to 10. Here, CYP19A1 is linked to Myalgia.