Osteopontin (OPN), a proinflammatory cytokine of the innate immune system, was first reported to be increased in the brains of SIVE-infected macaques and later in the plasma, CSF, and brains of HIV-infected individuals with cognitive impairment (Brown et al. 2011; Burdo et al. 2008). This evidence concerns the gene SPP1 and Cognitive impairment.