PECAM1 and Kaposi's sarcoma: Despite clinical and epidemiological differences, the classic, epidemic (acquired immunodeficiency syndrome-associated KS), endemic and post-transplantation associated KS lesions show a similar histopathology characterized by spindle shaped endothelial cells with latent KSHV infection expressing endothelial markers (CD31, CD34, CD36, and EN4), extensive neo-angiogenesis and inflammatory infiltration [21],[38],[39],[40].