HAVCR2 and Cognitive impairment: As expected, our study found that higher frequencies of CD4 and CD8 T cells single and double positive for PD-1, TIM-3, and/or TIGIT supports previous findings showing the relationship between lower clinical measures of immune function, such as lower current CD4 count, CD4/CD8 T cell ratio, and nadir CD4 T cell count and HIV cognitive impairment(Fenwick et al. 2019).