CX3CR1 and infection: Within the GP33-specific CD8+ T cells, a distinct splenic population of TCM cells expressing Sca-1 (Ly6A/E), Ly6C, CD11a (LFA-1 subunit), and CD27hi (Sp cluster 1) and a TEM cell population expressing CD54 (ICAM-1), KLRG1, and CX3CR1 (Sp cluster 6) connected to LM infection, whereas another TEM cell population characterized by higher levels of CXCR3, CD27hi, and CD127 (interleukin-7 receptor alpha [IL-7Rα]) (Sp cluster 2) was more abundant upon LCMV Armstrong infection (Figure 1G).