CD31-45

CD antigen	MW.(kDa)	Synonyms & Properties	Leukocyte expression	Function
CD31	130-140	GPiia, endocam, platelet endothelial cell adhesion molecule  (PECAM-1)	Endothelial cells, platelets, monocytes, neutrophils, NK cells, subsets of T cells	Adhesion molecule
CD32	40	FCRⅡ, FcγRⅡ	B cells, granulocytes, monocytes	Receptor for Fc portion of antigen-antibody-complexed IgG molecules
CD33	67	gp67, p67	Monocytes, myeloid precursors	Sialic acid-dependent cytoadhesion molecule, a sialoadhesion
CD34	40 (based on amino seq.)	gp105-120	Early lymphohematopoeitic stem and progenitor cells, small-vessel endothelial cells, embryonic fibroblasts, some cells in fetal and adult nervous tissue	Cell-cell adhesion molecule
CD35	Many forms: 160, 190, 220, 250, 165, 195, 225, 255	C3bR, C4bR, complement receptor type one (CR1), immune adherence receptor	Erythrocytes, neutrophils, monocytes, eosinophils, B cells	Receptor for C4b/C3b particles, mediating their adherence and phagocytosis; facilitator of C3b and C4b cleavage, thus limiting complement activation
CD36	88-113 (platelet form)	GPⅢb, GPIV, OKM5-antigen, PASIV	Platelets, mature monocytes / macrophages, endothelial cells	Adhesion molecule in platelet adhesion and aggregation, and in platelet-monocyte or platelet-tumor cell interaction; molecule for recognition of apoptotic neutrophils; scavenger receptor for oxidized LDL
CD37	40-52	gp52-50	B cells; low levels on T cells, neutrophils, granulocytes, and monocytes	Role in signal transduction
CD38	45	T10	Early-stage B and T cells, germinal-center B cells, plasma cells	NAD glycohydrolase
CD39	40-52	Bp50	B cells, T cells, neutrophils, granulocytes, monocytes	Role in signal transduction
CD40	48 (monomer)	Bp50	B-lineage cells (pro-B through plasma cells), macrophages, follicular dendritic cells, endothelial cells, fibroblasts, keratinocytes, CD34+ hematopoeitic cell progenitors	Roles in B-cell growth, differentiation, and isotype-switching; apoptosis rescue signal for germinal-center B cells; stimulation of cytokine production in macrophages and dendritic cells; up-regulation of adhesion molecules on dendritic cells
CD41	αβ dimer: α, 125; β, 122	GlycoproteinⅡb (GPⅡb) αⅡb integrin chain; forms platelet fibrinogen receptor by association with GP Ⅲa	Platelets, megakaryocytes	Subunit of platelet fibrinogen receptor, which mediates platelet aggregation by acting as receptor for fibrinogen; possibly also receptor for von Willebrand factor, fibronectin, and thrombospondin
CD42a,b,c,d	a, 23;   b, 135,23;   c, 22;	a, GPIX; b, GPIb-α; c, GPIb-β; d, GPV	Platelets, megakaryocytes	Adhesion of platelets to endothelium; amplification of platelet response to thrombin
CD43	95-115 in  T cells, 115-135 in neutrophils	gpL115, leukocyte sialoglycoprotein, leukosialin, sialophorin	All leukocytes except most resting B cells	Possible anti-adhesive ("barrier") molecule mediating repulsion between leukocytes and other cells
CD44	85	ECMR Ⅲ, H-CAM, HUTCH-1, Hermes, Lu, Pgp-1, gp85	Surface of most cell types	Adhesion molecule mediating leukocyte attachment and homing to peripheral lymphoid organs and sites of inflammation
CD44R	85-250 in epithelial cells; 85-200 in lymphocytes	CD44v, CD44v9; heterogenous group of CD44 variant isoforms designated by the variant exons that they include (v2-v10 in humans)	Epithelial cells and monocytes (constitutively), activated leukocytes	Possible role (particulary for CD44v6) in leukocyte attachment to and rolling on endothelial cells, homing to peripheral lymphoid organs and sites of inflammation
CD45	210, 220, 180, 200	Leukocyte common antigen (LCA), T200, EC 3.1.3.4; many dofferent isoforms with different molecular weights, e.g.. B220, CD45R, CD45RA, CD45RB, CD45RC, CD45RO	All hematopoeitic cells; different isoforms characteristic of differentiated subsets of various hematopoeitic cells	Essential role in T-and B-cell antigen-receptor-mediated activation; possible role in receptor-mediated activation in other leukocytes