KLRB1 and infection: Interestingly, both TB and HIV mono-infection were associated with statistically significant lower-level expression of the mucosal-homing receptor CCR6 on the CD161++ CD8+ T cell population compared to that observed in healthy individuals (median CCR6 expression in healthy subjects was 56.6%, in HIV mono-infection 37.3%; p = 0.0125, and in TB mono-infection 30.2%; p = 0.0284).