HL cell lines require relA, relB, and c-rel for maintenance of cell viability. (A-B) shRNA knockdown of RelB in the HL and NHL cell lines as indicated underneath the graphs. Each panel represents a different relB shRNA. (C-D) Ectopic relB expression (with PCR-introduced silent mutations that evades being targeted by the relB small hairpin) rescued the relB shRNA toxicity in HL cells. The line labeled “Ctrl” represents expression of the relB shRNA. The relB rescue is shown for 2 HL cell lines KM-H2 (C) and U-H01 (D). (E) shRNA knockdown of RelA and c-Rel in HL cell lines.