However, when patients were stratified by hormone receptor expression and age at diagnosis in a subsequent large study14, high expression of CYP27A1 mRNA was found to be specifically associated with improved RFS and OS among patients younger than 50 years presenting with ER+ disease only, lending clinical support to the preclinical experimental evidence that 27HC antagonizes estrogen-induced BC growth. The gene discussed is CYP27A1; the disease is breast cancer.