PDCD1 and neoplasm: Immunohistochemistry (IHC) and flow cytometric analysis indicated that the numbers of tumor-infiltrating and splenic CD8+, Granzyme B+CD8+ and TNF-α + CD8+ T cells were higher in mice treated with APG-2575 + PD-1 blockade than in those treated with any single drug alone (Fig. 1C–I, Supplementary Fig. S1H–J).