This antibody recognises a membrane antigen on rat macrophages, monocytes, dendritic cells and granulocytes. Like ED8, ED7 recognises small ramified microglia in the central nervous system. No other cell types are positive for ED7, except for the cilia of the bronchus epithelium. The recognised antigen is a heterodimer (160 and 95kD) belonging to the family of adhesion molecules (CD11b/CD18). ED7 and ED8 may recognise closely related epitopes on the same molecule. ED7 and ED8 have been shown to induce homotypic aggregation of granulocytes.