S100P is a 95-amino-acid protein and a member of the S100 family. S100P has been shown to mediate tumor growth, metastasis, and invasion through the binding of Ca2+ ions, the receptor for advanced glycation end products, cytoskeletal protein ezrin, calcyclin-binding protein/Siah-1-interacting protein, and cathepsin D.S100P highly expressed in human placenta, gastrointestinal tract, and esophageal mucosa, but always negative in pancreas and liver. Overexpression of S100P has been detected in several cancers such as breast, colon, prostate, pancreatic, and lung carcinomas, and the protein has been functionally implicated in carcinogenic processes. S100P could serve as a diagnostic marker, prognostic/predictive indicator, and therapeutic target for different carcinomas.