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). The gene discussed is PTH; the disease is obesity due to melanocortin 4 receptor deficiency.