Importantly, parameters of dysregulated immune function, particularly the CD4/CD8 T cell ratio, have been linked to non-AIDS comorbidities, including subclinical atherosclerosis, lower renal function, muscle wasting, and to worsening cognitive function (Bernal Morell et al. 2016; Fenwick et al. 2019; Grauer et al. 2015; Serrano-Villar et al. 2014a, b) and that the exhausted T cell population may serve as a more accurate functional marker of HIV-associated comorbidities beyond the central nervous system. Here, CD4 is linked to AIDS.