PTH and Obesity: In this review, we summarize the functional heterogeneity of BMSC subpopulations in the different development stages (e.g., embryonic development, adulthood, and aging), various environmental stresses (like loading, microgravity, hypoxia, irradiation as well as parathyroid hormone (PTH)) (Figure 1 and Table 1), and different pathological conditions (such as fracture, osteoporosis, heterotopic ossification, obesity as well as acute myeloid leukemia (AML)) (Figure 1).