BRD4 and cancer: SRX3177 is a “first in class” triple PI3K-BRD4-CDK4/6 inhibitor, for combinatorial inhibition of three oncogenes promoting cancer cell growth: phosphatidylinositol-3 kinase (PI3K), cyclin-dependent kinases 4 and 6 (CDK4/6), and the epigenetic regulator BRD4 [162] in a single molecule.