Clinical studies have confirmed the following findings: the incidence of the Fok-I variant of the vitamin D receptor in Caucasian women is about 33%; IL-1β is a cytokine closely related to arthralgia; IL-1β levels are reduced by around 50% in women with this variant; patients are less likely to report abnormal arthralgia and myalgia six months after the initiation of AI therapy (40, 40). This evidence concerns the gene IL1B and Myalgia.