CAMPATH-1 antigen (also known as CD52) is a very small glycosylphosphatidylinositol (GPI)-anchored glycoprotein present in lymphocytes , male reproductive tracts and female cumulus cells [, , , , ]. CD52 on the lymphocyte membrane surface induces regulatory T cells with immunosuppressive activities []. In the male reproductive tract, CD52 may protect sperm function from complement attack if antisperm antibody is generated in the female reproductive tracts []. It has also been suggested that CD52 has some functional roles around fertilisation in females as well as in males [].
