EP300 and plasma cell myeloma: While BET proteins are known to similarly target MYC in multiple myeloma, a comparison of CBP/EP300 and BET bromodomain inhibition demonstrated that these modalities target the IRF4-MYC network at different nodes, with BET inhibition having no impact on IRF4 at the doses and timepoints examined (Figure 6E, Figure 3D, and Figure 4—figure supplement 1B).