C-type lectin-like receptor 2 (CLEC-2) has been identified as a receptor for the platelet-activating snake venom rhodocytin. An endogenous ligand of CLEC-2 is the membrane protein podoplanin (PDPN), which is expressed on the surface of certain types of tumor cells and lymphatic endothelial cells (LECs). Deletion of CLEC-2 from platelets in mice results in death just after birth due to lung malformation and blood/lymphatic vessel separation. CLEC-2 protein is highly expressed in platelets and megakaryocytes and at lower levels in liver Kupffer cells and liver sinusoidal endothelial cells in humans. In mice, CLEC-2 is also expressed in neutrophils, dendritic cells, and macrophages at low levels.