CX3CR1 and neoplasm: In contrast, MPE CD8+ T cells had the highest proportion of CX3CR1+KLRG1+ effector T cells (5.6% in MPE vs. 2.9% in tumor vs. 2.8% in blood), the lowest proportion of CD45RA+CCR7+ naïve T cells (Tn; 7.9% in MPE vs. 9.6% in tumor vs. 22.7% in blood), and intermediate expression of multiple co-inhibitory receptors (Figure 1C, 1E, 1H; Figure S6A).