KDM4B and osteoporosis: As a result, aged bones exhibit significant reduction in overall bone volume and bone mass regardless of gender or ethnicity, entailing considerable risks for fracture, osteoporosis, and diminished functions.32 Interestingly, our lab has revealed that the histone demethylase KDM4B promotes the osteogenic commitment of MSCs while inhibiting adipogenic differentiation, indicating that epigenetic regulation may play a vital role in determining the MSC cell fate in skeletal aging and metabolic bone diseases.33