IGF1 and osteoporosis: To explore the molecular mechanism of exosomal miR-140-5p inhibiting osteogenesis through IGF1R, we mainly examined the mTOR pathway related to the osteogenic differentiation of hMSCs because it has been reported in the literature that the combination of IGF1 and IGF1R can promote the osteogenesis of MSCs by activating the mTOR pathway, resulting in improvement of osteoporosis in mice [23].