Bromodomain and extraterminal (BET) protein inhibition of IgG/IgE production in murine B cells is counter-balanced by a strong Th2 bias.

Altogether, BET inhibition thus interweaves intrinsic negative effects on B cells with a parallel complex reshaping of T-cell polarisation which can increase type 2 cytokines and eventually promote B-cell-dependent immunopathology. These opposite and potentially hazardous immunomodulatory effects raise concerns for clinical use of BET inhibitors in patients with immune disorders.