Podoplanin, a small transmembrane glycoprotein, is expressed at high levels on lymphatic
endothelial cells, kidney podocytes and lung type I alveolar cells, but absent on blood
endothelial cells. It has also been described on splenic and peritoneal macrophages, but the
functional significance of this is unknown [1]. Podoplanin is an endogenous ligand for CLEC-
2, a C-type lectin expressed on platelets and at a lower level on subsets of other
hematopoietic cells [2–4]. The interaction of CLEC-2 on platelets with podoplanin on …