PDCD1 and neoplasm: IFN signaling increases the expression of PD-L1 in tumor tissue during ICI treatment40 and has been associated with predicting response to ICIs in some patients.41 Eventually, sPD-L1 might also be involved in suppressing the PD-1-mediated negative regulation of the T-cell response with an effect similar to that of sPD-1.36 42