Figure 2. ZMPSTE24 protein expression during murine aging. ZMPSTE24 protein levels were determined by Western blots from brain, liver, heart, gastrocnemius, and subcutaneous fat of young (9 months of age, n = 5) and old (22 months of age, n = 5) female mice. Relative ZMPSTE24 levels (normalized to GAPDH) were quantified by densitometry using ImageJ software (