CD8A and neoplasm: Comparison of immune infiltrates between the RRShigh and RRSlow groups showed that the infiltration of CD8+PD-1+ T cells was significant higher in both tumor center and stroma in the RRSlow group than in the RRShigh group (Fig. 5d, e), suggesting that exhausted PD-1+CD8+ T cells with impaired tumor-killing capacity might contribute to the worse prognosis of RRSlow patients.