RELB and Miyoshi myopathy: As shown in Figures 4G, RelA protein levels were efficiently repressed in RPMI-8226, U266 and LP1 cells infected with a lentivirus carrying a shRNA directed against RelA compared to what is seen in the empty-virus infected cells; and apoptosis was markedly increased in RPMI-8226 and U266 cells, and to a lesser extent in LP1 cells (mean: 14% versus 33% in RPMI-8226, 15% versus 31% in U266, 12% versus 18% in LP1), thus indicating that overall NF-κB activation, including both RelA and RelB, is critical for MM cell survival.