Ibrutinib inhibits BCR-activated adhesion of MCL cells. (A-B) Jeko1 or HBL2 cells pretreated with 100 nM ibrutinib or DMSO vehicle were stimulated with anti-IgM for 0, 0.5, 1, 2, 5, or 10 minutes and then immunoblotted for pBTK (Y223), pERK, and pAKT. (C-D) Jeko1 and HBL2 cells pretreated with drug were subjected to adhesion assays on plates precoated with anti-IgM and either (C) fibronectin or (D) VCAM-1. PMA stimulations were used as a positive control for the assay and to show specificity of drug response. The n values represent the number of independent experiments performed in triplicate; the average of these experiments is displayed. **P < .01; ***P < .001. One-way ANOVA compared with vehicle control. PMA, phorbal 12-myristate 13-acetate.