Standard adjuvant therapy in the early 1990s consisted of oral fluoropyrimidines or classic cyclophosphamide + methotrexate + fluorouracil and anti-estrogenic drug.28–30 Subsequently, anthracycline + cyclophosphamide and taxan have been widely used since the late 1990s to early 2000s.31 Aromatase inhibitors were approved in 2001 and have been shown to be superior to anti-estrogen drugs in the prevention of recurrence of postmenopausal breast cancer.32 The gene discussed is CYP19A1; the disease is breast cancer.