PDCD1 and neoplasm: The expression of PD-1 in TIMC, PD-L1 in tumor cells, PD-L1 in TIMC, and CTLA-4 in TIMC was detected in 9.4% (31), 12.3% (41), 4.8% (16), and 6.3% (20), respectively (Figure 1, Table 1).