CD36 is a type-B scavenger receptor that is necessary for the formation of foam cells and thereby atherosclerotic lesions.1,2,3,4 This membrane glycoprotein can internalize fatty acids which activate proliferator-activated receptor ã and stimulate further expression of CD36.5,6 This positive feedback loop combined with the murine CD36 knock-out studies reinforces the importance of CD36 in lipid metabolism. Additionally CD36 is needed for the phagocytosis of P. falciparum infected erythrocytes, retinal pigment epithelial cell photoreceptor fragments and post-apoptotic monocytes and neutrophils.7,8,9,10 CD36 expression has been monitored during hematopoietic cell differentiation and may be an indicator of tumor spreading in lymphocytic leukemia.11 Positive controls include adipose and heart tissue, platelets, and macrophages. Note: mAb clone JC63.1 is also known as clone CRF D-2723 and clone 63.