ERN1 and neoplasm: Furthermore, since PD-L1 serves as the ligand for PD-1+ T cells with an exhausted [71] or a regulatory phenotype [72], a plausible conclusion from the present study is that IRE1α inhibition in tumor-infiltrating myeloid cells could be used therapeutically to ameliorate the effects of immune dysregulation in the TME, including the down-regulation of PD-L1.