CD28 and neoplasm: Cluster1 of CD28− T cells (KLRG1+EOMES+CD28−), highly represented in the periphery and under-represented at the tumor site, showed transcriptional features of long-lived memory T cells with effector potential, partially shared with cluster0 of the CD28+ T-cell subset (KLRG1+EOMES+CD28+) (Fig. 7F and Table S4, S5).