PDCD1 and neoplasm: Immunofluorescence (IF) staining demonstrated highly expressed Usp24 in tumor-infiltrating CD8+ T cells with PD-1+Tim-3+ exhaustion features from Usp24WT mice (Fig. 1, H and J), while it was less frequent in lung tumors from Usp24C1695A mice (Fig. 1, I and J).