Immune checkpoint-blockade treatments targeting PD-1/PD-L1 have revolutionized cancer therapy. Hence, understanding the regulation of PD-L1 expression has major clinical relevance. In this issue of Cancer Cell, Lim et al. report that inflammation-induced and NF-κB-driven expression of deubiquitinating enzyme CSN5 leads to PD-L1 stabilization and immune suppression in tumors.