Ibrutinib blocks CD4⁺ and CD8⁺ T-cell activation in anti-CD3 stimulated T cells in a BTK-independent manner. (A-B) T lymphocytes obtained from spleen of indicated genotypes were stimulated with anti-CD3ε Abs in the presence of indicated concentrations of ibrutinib and subsequently analyzed by flow cytometry for the activation markers CD69 and CD25. Representative data from 1 of 2 independent experiments. (A) Prior gating is indicated below the FACS plots. (B) Bars indicate mean with SD from 2 biological replicates.