The homologous drug OTX015, a first‐in‐class small molecule inhibitor (MK‐8628), has been applied in a clinical phase 1 dose‐escalation study in acute myeloid leukemia, lymphoma, and multiple myeloma.36 BET inhibitors exert antitumor effects through their high affinity to the BD pockets.14 However, the present results demonstrate that GLTSCR1 binds to the BDs independent of the acetyl‐lysine binding pocket but interacts strongly with the PDID in a manner dependent on the phosphorylation of the Ser492 and Ser494 sites on BRD4. This evidence concerns the gene BICRA and AL amyloidosis.