Background：Kidney specific calcium binding protein （Ksp-Cadherin） is a new member of cadherin family. This protein has a kidney specificity. In kidney tissue, Ksp-Cadherin is only expressed in renal tubular epithelial basement membrane and collecting duct epithelium, and not expressed in glomerular, renal interstitial cells and vessels. Many different calcium （the E-cadherin N- cadherin, Cadherin Delta etc.） in renal cell tumors have confirmed that the loss of these adhesion molecules may be related with tumor dedifferentiation and lymph node metastasis. Research of Shen et al. have showed that Ksp-Cadherin has a high sensitivity up to 100％ （13/13） in chromophobe renal cell carcinoma, and 95％ （19/20） in renal oncocytoma.
