Future research examining the association between psychosocial factors and pain outcomes in HIV should consider controlling for such variables as age, sex/gender, race/ethnicity, socioeconomic status, HIV duration, current and nadir CD4+ count and current and peak viral load, current and past ART regimens, and other medical comorbidities (eg, hepatitis C, diabetes, and tuberculosis). This evidence concerns the gene CD4 and hepatitis C virus infection.