PPAR-gamma, a transcription factor involved in adipogenesis, glucose homeostasis, bone turnover, and inflammation, has now been shown to increase klotho expression. Klotho is predominantly expressed by the kidney and functions at the tubule and in the circulation as an anti-aging factor and a hormone participating in mineral metabolism. The finding that klotho is upregulated by PPAR-gamma may prompt further exploration of the role and mechanism of action of PPAR-gamma in aging and bone diseases.