KL and osteoporosis: first reported that the mutation of Klotho gene in mice could lead to a series of phenotypes similar to premature aging, including growth retardation, arteriosclerosis, osteoporosis and shortened life span, thus revealing the important role of Klotho in the regulation of aging (13, 14).Subsequent studies have found that Klotho is not only an anti-aging molecule, but also involved in mineral metabolism, energy homeostasis, oxidative stress regulation, apoptosis and fibrosis (15, 16).