In addition to hemostasis and host defense, platelets are involved in the induction of inflammation, tissue repair, and tumor metastasis. Aggrus (T1a/Podoplanin) is a novel 36-45 kDa membrane sialoglycoprotein that induces platelet aggregation. Aggrus is highly expressed in various tumor cells and the platelet aggregation ability of Aggrus depends on specific oligosaccharide structures that may be related to the metastasis process in cancer cells. Aggrus has been identified as a diagnostic tumor marker for seminomas and testicular cancers.Synonyms: Aggrus, GP36, Glycoprotein 36, PA2.26 antigen, PDPN, PSEC0003, PSEC0025, T1-alpha