Mouse anti human podoplanin antibody, clone D2-40 was raised against M2A antigen and detects podoplanin. Podoplanin (PDPN) is an O-glycosylated transmembrane glycoprotein that is selectively expressed by, and is a marker of, lymphatic endothelial cells. In normal tissue the 38 kDa protein is also present in human lung, placenta, heart, skeletal muscle and kidney podocytes. It is not found in the blood vasculature. The function of podoplanin is yet to be fully elucidated; however, it may be involved in cell migration and/or actin cytoskeleton organization. It is required for normal lung cell proliferation and alveolus formation at birth, and can induce platelet aggregation. Mouse anti human podoplanin antibody, clone D2-40 has been shown to be a sensitive and specific antibody for the detection of lymphatic endothelium in different malignancies, and is of value in the routine evaluation of lymphatic invasion in esophageal cancer. Clone D2-40 was reported to be an excellent immunohistochemical marker of cutaneous Kaposi’s sarcomas, and may be useful in the differential diagnosis of epithelioid malignant mesothelioma versus adenocarcinoma.