- CCR5, GPR15, and CXCR6 are major coreceptors of human immunodeficiency virus type 2 variants isolated from individuals with and without plasma viremia. Blaak, H., Boers, P.H., Gruters, R.A., Schuitemaker, H., van der Ende, M.E., Osterhaus, A.D. J. Virol. (2005)