C-type lectin domain family 1 member B (CLEC1B, CLEC2) is a 32-kDa C-type lectin-like receptor that dimerizes to form the platelet receptor for the snake venom toxin rhodocytin and the endogenous lymphatic endothelial marker, podoplanin (PDPN) (Suzuki-Inoue et al. 2006, 2007, Christou et al. 2008, Watson et al. 2009). PDPN is a sialomucin-like glycoprotein with a wide tissue distribution. It is found at a high level in lung type I alveolar cells, kidney podocytes, choroid plexus epithelium, lymphatic endothelial cells and fibroblastic reticular cells within secondary lymphoid organs. PDPN is not found on vascular endothelial cells. It is up-regulated in a variety of tumors and on macrophages following lipopolysaccharide stimulation. Cells expressing PDPN or recombinant forms of its extracellular domain have been shown to induce platelet activation (Pollitt et al. 2014).