CDK9 is a target in constant development in cancer therapy. CDK9 inhibitors have demonstrated good antitumoral activity in vitro. Although there are many small molecules that bind CDK9, the lack of selectivity against other CDKs and enzymes does not allow their clinical use. However, drug designers have the tools required to improve the selectivity of CDK9 inhibitors.
Morales F, Giordano A. Overview of CDK9 as a target in cancer research[J]. Cell Cycle, 2016, 15(4): 519-527.