Klotho expression has been shown to be significantly down-regulated in malignant tissue compared to adjacent non-malignant tissue using immunohistochemical (IHC) techniques, including colorectal [44,45], pancreatic [46], gastric [47], oesophageal [48], breast [49], hepatocellular [50], ovarian [51], and renal cancers [52] (Table 1). This evidence concerns the gene KL and renal carcinoma.