References: Bour S, Boulerice F, Wainberg MA. Inhibition of gp160 and CD4 maturation in U937 cells after both defective and productive infections by human immunodeficiency virus type 1. J Virol. 1991 Dec;65(12):6387-96. (OKT4, IP, PubMed)
Reinherz EL, Kung PC, Goldstein G, Schlossman SF. 1979. Separation of functional subsets of human T cells by a monoclonal antibody. Proc Natl Acad Sci. 76(8): 4061-5.