Sustained activation of NF-κB is prevalent in cell lines and tumor tissue specimens and contributes to malignant progression and therapeutic resistance in most of the major forms of human cancer.21 As a newly approved drug for multiple myeloma, the proteasome inhibitor bortezomib (VELCADE) can inhibit the degradation of IκBα and subsequently inhibit NF-κB signaling pathway.22 Since NF-κB is a popular cancer drug target, the identification of RCAN1 as an NF-κB inhibitor provides a potential treatment for cancers in which NF-κB signaling is aberrantly activated. Here, NFKB1 is linked to cancer.