CDD-1653 is a potent and selective BMPR2 inhibitor ( IC 50 =2.8 nM). CDD-1653 reduces the ability of ATP to bind to the kinase domain of BMPR2 , thereby affecting the phosphorylation of SMAD1/5/8 transcription factors, which play a key role in the BMP signaling pathway. CDD-1653 can be used to study diseases related to the BMP signaling pathway.