Therefore, it is suggested the existence of a relative threshold between CCL5/RANTES expression levels in the CNS of the infected individual for their effective immune response against the pathogen, through the CCL5–CCR5 axis, as many studies in this review also concluded a beneficial organic role in the evolution of the neurological clinical picture related to the elevation of the levels of this chemokine (all at a concentration of CCL5/RANTES ≤ 20 nM) in the blood of individuals with AIDS. The gene discussed is CCL5; the disease is AIDS.