Cadherins are a family of transmembrane glycoproteins that mediate calcium-dependent cell-cell adhesion and play an important role in the maintenance of normal tissue architecture. N-cadherin (neural cadherin), also known as CDH2 (cadherin 2), is a 130-kDa transmembrane protein and a classical member of the cadherin superfamily which also include E-, P-, R-, and B-cadherins. Expression of N-cadherin has been reported on various cell types including neurons, endothelial cells and cardiac myocytes. N-cadherin has functions in early brain morphogenesis, synaptogenesis and synaptic plasticity. Soluble N-cadherin (sN-CAD) is found in biological fluids, including serum, seminal fluid samples, and urine. It has been shown that significantly higher amounts of serum sN-CAD are present in cancer patients than in persons with no evidence of disease.