The abbreviation Rhesus factor (RH factor) stands for Rhesus factor. A protein located on the surface of red blood cells is called Rh factor. "It is a chemical found in most people's red blood cells that can induce the formation of antibodies in the blood," the Cambridge Dictionary says. The RHD gene that produces the RhD protein with the D antigen (and variants) and the RHCE gene that produces the RhCE protein with the C, E, c, and e antigens...