STAT1 and gastric cancer: Relevant to both OSCC and EBV+-gastric cancer, JAK2/STAT1 signaling has been shown to mediate respectively EGFR- or IRF-1, IFNγ-induced upregulation of the programmed cell death-ligand 1 (PD-L1), an inhibitor of T-cell-mediated tumor cytotoxicity (152, 153) as discussed later in this review.