The CBM complex impedes the BCMA-induced activation of NF-κB. (A-C) Flag-BCMA protein was overexpressed in MALT1-KO IM9 cells. BCMA expression was detected by WB assay (A). Cell viability of these cells was detected for 4 consecutive days by CCK-8 assay (B). WB analysis of p65 and p-p65 in cells treated as indicated in the panel. GAPDH was used as control (C). (D) BCMA-overexpressing cells were treated with Mi-2 for 4 hours, and p-p65 was detected by WB assay. GAPDH was used as control. (E) IM9 or H929 cells were treated with APRIL (200 ng/mL) in absence or presence of Mi-2 (1.5 μM) for 4 hours, p-p65 was detected by WB assay. (F) RPMI8226 cells with shMALT1 and scramble were cultured with APRIL (200 ng/mL) for 4 hours, and levels of p-p65 and p-IκB level were detected by WB assay. (G-H) IM9 cells were transduced with sgRNA targeting CARD11. The protein expression level of CARD11 was detected by WB (left), and cell viability of these cells was assessed by CCK-8 assay (right) (G). p-p65 and p-IκB were detected by WB assay in absence or presence of APRIL (200 ng/mL) (H). I-J. IM9 cells were transduced with sgRNA targeting BCL10. The protein expression level of BCL10 was detected by WB (left), and cell viability of these cells was assessed by CCK8 assay (right) (I). p-p65 and p-IκB were detected by WB assay in absence or presence of APRIL (200 ng/mL) (J). ns, P > .05; ∗P < .05; ∗∗P < .005; ∗∗∗P < .001; and ∗∗∗∗P < .0001.