APLN and osteoporosis: Apelin modulates cell survival and differentiation in bone marrow-derived mesenchymal stem cells (BMSCs) and other cell types by regulating processes such as autophagy, apoptosis, and inflammation, thereby exerting a protective role in bone-related disorders including osteoporosis, fracture healing, arthritis, and periprosthetic osteolysis (Gong et al., 2023).