SRX3212 is a Novel BRD4 PI3Kα inhibitor, displaying an IC50 of 3.7 nM toward BRD4BD1 and 32 nM toward BRD4BD2, and therefore was~65-fold more potent inhibitor of BRD4BD1 and~48-fold more potent inhibitor of BRD4BD2 than SF2523 (GLXC-10641), retaining its high inhibitory activity for PI3Kα (IC50: 22 nM).