TIGIT and neoplasm: Tumor CD8+ T cells were also most enriched with CD103+CD69+ resident memory T cells (Trm; 24.6% in tumor vs. 8.4% in MPE vs. 0.3% in blood; Figure 1D) and exhibited the highest expression of the co-inhibitory receptors PD-1, LAG-3, TIGIT, and TIM-3 (Figure 1H; Figure S6A).