Of note, PIs have been indicated to imply their anti-tumor effects through different mechanisms, including UPR and ER stress, NF-κB signaling interruption, accumulation of pro-apoptotic proteins, DNA repair dysregulation, and tumor angiogenesis inhibition; however, cases of PI resistance have been reported in MCL [19, 176]. Here, NFKB1 is linked to mantle cell lymphoma.