While the level of impairment in the HIV+ group is akin to another study in patients with high CD4 cell counts and cART initiation always above CD4 of 350 cells/mm3 (despite different methods it was 20%) (Wright et al., 2015), the rate of impairment in the HIV- sample was very unusual and akin to a clinical population with a history of traumatic brain injury (Rabinowitz et al., 2015), condition that is prevalent in the U.S. military (Helmick et al., 2015). This evidence concerns the gene CD4 and brain injury.