ITIH4 and HIV-1 infection: Studies have found that the Tys177 sulfated peptide pV2α-Tys (amino acids 168–185) derived from the V2 loop can serve as a structural and functional mimetic of the N-terminus of CCR5, acting directly on the CoRbs on the gp120 V3 loop in a CD4-dependent manner, thereby blocking the binding of gp120 to the coreceptor and inhibiting HIV-1 infection [85].