CXCR4 and infection: For example, Cxcr4 acts also as a main co-receptor for cellular entry of T-tropic strains of HIV-1 at late stages of infection and in individuals with acquired immune deficiency syndrome-associated dementia complex (ADC), who develop a spectrum of motor impairments and dementia (Bachis et al., 2006; Bleul et al., 1996).