KLRG1 and HIV infectious disease: It can be also argued that as CD153-expressing CD4 T cells exhibit a low level of memory differentiation and activation (with increased CD27 expression and lower KLRG1, Eomes, and HLA-DR expression compared to their CD153− counterparts, Fig. 5b), these cells could be less susceptible to HIV infection, as HIV preferentially targets activated cells.41,42