NFKB2 and plasma cell myeloma: The direct regulation of PLUM expression by NF-κB/p52 was further confirmed by CRISPR-mediated KD of NF-κB/p52 in two NF-κB mutant multiple myeloma cell lines (MMCLs), KMS11 and LP1, which resulted in the downregulation of PLUM expression (Supplementary Fig. 1a, b).