CD274 and neoplasm: Strikingly, proteasome inhibition (for a longer period) increased overall PD‐L1 in tumor cells lysates (Fig 2K) and DR5 agonist plus MG132 co‐treatment did not additionally stabilize PD‐L1 on cell surface or in total lysates (Figs 2H–J, and EV2G, Appendix Fig S5A).