Furthermore, more than ten single nucleotide polymorphisms (SNPs) have been identified in the human KLOTHO gene, and a number of studies have been performed to evaluate the associations between allelic variations in the KLOTHO gene and the aetiology of ageing-related diseases [53,54,55,56,57,58,59,60,61], including the effect of Klotho’s functional variants on cancer predisposition [62,63,64]. This evidence concerns the gene KL and cancer.