AR and osteoporosis: Growing evidence suggests that the expression levels of many autophagy genes are regulated by sex hormones, such as estrogens and their receptors, contributing to the distinction between autophagy-mediated osteoporosis in men and women (Fig. 4d).272–276 For instance, ATG3 is regulated by AR only, whereas Unc-51-like autophagy activating kinase 1 (ULK1) is the target gene, with its transcription level regulated by both AR and ERα.