Additionally, the immunosuppressive cell-related signature (i.e., Treg cells, tumor-infiltrating Treg cells (TITRs), myeloid-derived suppressor cells (MDSCs)) and PD-1 signaling were upregulated in the immune-suppressed subclass compared with those in the immune-activated subclass (Figure 2A). The gene discussed is PDCD1; the disease is neoplasm.