Anti-CD4 (human), clone QS4120

Human CD4 is a cell surface glycoprotein of 55kDa expressed on most thymocytes, on about two thirds of peripheral T cells and on some monocyte macrophage lineage cells. CD4 interacts with MHC Class II molecules in an accessory role during foreign antigen recognition by T cells. The extracellular portion of CD4 is an array of four Ig-like domains. The N-terminal region of CD4 is a receptor for the HIV-1 viral protein gp120.