FGF21 and sarcopenia: Since we previously reported that there was fat accumulation in the bone marrow of Fgf2KO mice with age16, we examined whether there was accumulation of fat and other markers of sarcopenia in skeletal muscle of Fgf2KO and whether there was associated modulation of the myokine FGF21 that has been reported to be associated with increased skeletal muscle fat accumulation and altered adipogenic and FGF receptor signaling.