We used double-label immunohistochemistry and antibodies to CD68 and Iba-1/AIF-1 to specifically identify macrophage/microglia in brain tissue from uninfected controls, HIV+ ANI, HIV+ MND/HAD, and a group with a well-known neurodegenerative disease affecting motor neurons, amyotrophic lateral sclerosis, ALS. The gene discussed is CD68; the disease is neurodegenerative disease.