KLRG1 and head and neck squamous cell carcinoma: Together with additional datasets containing single cell RNA-seq gene expression data from human cancer biopsies, KLRG1+ TILS accounted for 16-48% of CD8+ TILS, a frequency similar to that of PD-1+ TILS, in renal cell carcinoma, hepatocellular carcinoma, melanoma, ovarian cancer, HNSCC, and astrocytoma (Figure 1E, 1F).