Interestingly, SE location and IRF4 occupancy in PEL cell lines were at least in some instances distinct from those seen in other IRF4-dependent cell lines, i.e., the LCL GM12878 (60), multiple myeloma cell line KMS-12-BM (31), and HTLV-1 transformed ATLL cell line ST-1 (27). The gene discussed is IRF4; the disease is plasma cell myeloma.