MBZ was shown to suppress cell proliferation and/or induce apoptosis through inactivating C-MYC pathway in malignant ascites cells and gastric cancer cells [47], inhibiting USP5/c-Maf axis in multiple myeloma [48] or TRAF2- and NCK-interacting kinase (TNIK) in colon cancer cells [49], and downregulating XIAP expression in melanoma cells [50]. Here, XIAP is linked to plasma cell myeloma.