KL and hyperphosphatemia: While hyperphosphatemia is known to stimulate pro-inflammatory, pro-aging and pro-fibrotic signals to exacerbate renal and cardiovascular damage (6), the mechanisms by which active vitamin D induces expression of the FGF23 and α-klotho genes to attenuate the pro-aging effects of hyperphosphatemia and maintain the plethora of anti-aging/pro-survival actions of renal and circulating klotho are not fully understood (7).