This study was designed to (a) confirm the potential role of sKlotho as an early biomarker of CKD-MBD, (b) to assess whether sKlotho is a reliable indicator of kidney α-Klotho content, (c) to deepen the effects of sKlotho on VSMCs osteogenic differentiation and (d) to evaluate if autophagy could be involved in the actions of sKlotho. The gene discussed is KL; the disease is chronic kidney disease.