PNN, also named as DRS or 140 kDa nuclear and cell adhesion-related phosphoprotein, is a 717 amino acid protein, which belongs to the pinin family. PNN localizes in the plasma membrane and is expressed in placenta, lung, liver, kidney, pancreas, spleen, thymus, prostate, testis, ovary, small intestine, colon, heart, epidermis, esophagus, brain and smooth and skeletal muscle. PNN is expressed strongly in melanoma metastasis lesions and advanced primary tumors. PNN as a transcriptional activator binds to the E-box 1 core sequence of the E-cadherin promoter gene. PNN is involved in the establishment and maintenance of epithelia cell-cell adhesion. PNN is a potential tumor suppressor for renal cell carcinoma.