The explanation as to how the Klotho level is associated with tau pathology is still unclear, but it has been linked to several biological processes, including calcium signaling,37 growth factor functions,38 insulin regulation,3 and reactive oxygen species regulation, thereby decreasing neuronal damage.39,40 It has also been speculated whether Klotho’s involvement in autophagy might be associated with the clearance of AD-related proteins.41,42. Here, KL is linked to Alzheimer disease.