- Activity of different bicyclam derivatives against human immunodeficiency virus depends on their interaction with the CXCR4 chemokine receptor. Esté, J.A., Cabrera, C., De Clercq, E., Struyf, S., Van Damme, J., Bridger, G., Skerlj, R.T., Abrams, M.J., Henson, G., Gutierrez, A., Clotet, B., Schols, D. Mol. Pharmacol. (1999)