Recently, Li and colleagues demonstrated that T cells expanded from PD-1+ peripheral blood lymphocytes, compared with their PD-1− counterparts, share more T-cell receptor (TCR) clones with paired TILs by comparing the TCR repertoire of these three populations, providing further evidence for the tumor reactivity of PD-1+CD8+ T cells in circulating blood (18). Here, CD8A is linked to neoplasm.