A. Karpas 299 cells were electroporated with siControl, siA-1/3, siA-1, siRelB and siA-1, or siRelB, and 48 hours later, protein levels were analyzed by immunoblotting with the antibodies shown. B. Cell proliferation was measured in Karpas 299 cells, after introduction of siControl, siA-1/3, siA-1, siRelB and siA-1, or siRelB, by counting them every 24 hours for 72 hours. C. Cell cycle analysis using propidium iodide was performed 48 hours after transfection of Karpas 299 cells with siControl, siA-1/3, siA-1, siRelB and siA-1, or siRelB. D. qPCR analysis of CDKN1A and CDKN2B gene expression in Karpas 299 cells 48 hours after electroporation with the indicated siRNAs. E. qPCR analysis of noncanonical NF-κB target genes using total RNA isolated from Karpas 299 cells electroporated as in A. F. Karpas 299 cells were electroporated with siControl, siA-1, siRelA and siA-1, or siRelA and protein levels were analyzed 48 hours later by immunoblotting. β-actin serves as a loading control. G. Cell cycle analysis of Karpas 299 cells treated as in F. H. Forty-eight hours post-transfection, qPCR analysis of RELB expression was performed using total RNA isolated from Karpas 299 cells that had been electroporated with siControl, siA-1/3, or siA-1. I. Karpas 299 cells electroporated with siControl, siA-1/3, or siA-1 were treated with 100 μg/mL cycloheximide at 60 hours post-transfection and lysed at the indicated time points. Cell lysates were analyzed by immunoblot for changes in RelB half-life. The β-actin immunoblot corresponds to the siControl sample and is similar to β-actin levels from the siA-1/3 and siA-1. *p < 0.001 compared to siControl. **p < 0.001 compared to siA-1.