NFKB1 and neoplasm: It reversibly inhibits the activities of chymotrypsin- and caspase-like enzymes, leads to the apoptosis of MM cells, and suppresses the activation of NF-κB, production of cytokines (e.g., IL-6, IGF-1, and VEGF) in the tumor microenvironment, and adherence of myeloma cells to bone marrow stromal cells (165, 168).