The peptide T22 (|Tyr5,12, Lys7|-polyphemusin II) is polyphemusin-derived and shows strong inhibitory effects against CXCR4; it was one of the first modified peptides with a potent HIV response and the 50% inhibitory concentration useful to fight AIDS, similar to AZT (3′-azido-3′-deoxythymidine), initially used for the treatment of the human disease [76]. Here, CXCR4 is linked to AIDS.