DRD1 and breast cancer: In addition, blood vessel formation and osteoclastic resorption are two other key factors in GC‐associated ONFH.[52] DRD1 has been shown to inhibit high glucose‐induced apoptosis via upregulating the CSE/H2S pathway in vascular endothelial cells.[53] DRD1 activation can also suppress the development of bone‐resorbing osteoclasts by elevating the eIF2α phosphorylation in breast cancer and bone metabolism.[42] Thus, the potential role of DRD1 in improving vascularization and osteoclastogenesis would be important to investigate in ONFH progression.