A, Schematic of CBM signaling downstream of GPCRs, highlighting the dual role of MALT1 as a protease and as a scaffolding protein, both of which are activities that contribute to NF-κB activation. B, Effect of pharmacologic MALT1 protease inhibition on expression of Snail and ZEB1. BT549 cells were treated ± 10 μM mepazine or 5 μM thioridazine for 2 days before harvesting and immunoblot analysis. C, Effect of pharmacologic MALT1 protease inhibition with the s-enantiomer of mepazine. BT549 or MDA-MB-231 cells were treated ± 10 μM s-mepazine for 2 days before harvesting and immunoblot analysis.