AT7519 HCl is a potent inhibitor of cyclin-dependent kinases (CDKs), particularly CDK1, CDK2, CDK4, and CDK9. It is primarily investigated for its anticancer properties due to its ability to disrupt cell cycle progression and inhibit transcription in tumor cells. By blocking CDK activity, AT7519 HCl induces apoptosis and suppresses proliferation in various cancer cell lines, including leukemia, multiple myeloma, and solid tumors. It has shown promising results in preclinical studies as a therapeutic agent, especially in hematological malignancies. Its mechanism of targeting CDK9 also affects the expression of short-lived oncoproteins like Mcl-1, which are critical for cancer cell survival. Due to this, AT7519 HCl is often studied in combination with other anticancer agents to enhance efficacy and overcome drug resistance. Additionally, it serves as a research tool in molecular biology to study CDK-mediated signaling pathways and cell cycle regulation. Its selectivity and potency make it valuable in developing new kinase-targeted therapies.