Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.

Synonyms: Antigen, Cell Surface, Surface Markers, Immunologic, Immunological Surface Markers, Immunologic Surface Markers, Surface Antigen, Cell Surface Antigen, Surface Antigens, Cell, Surface Antigen, Cell, Surface Antigens, Markers, Immunological Surface, Antigen, Surface, 0, Cell Surface Antigens, Surface Markers, Immunological, Antigens, Surface, Antigens, Cell Surface, Markers, Immunologic Surface