CDK9-IN-2 is primarily used in research settings to study the role of cyclin-dependent kinase 9 (CDK9) in various cellular processes. It is a potent inhibitor of CDK9, which plays a critical role in transcription regulation by controlling the elongation phase of RNA polymerase II. Researchers utilize this compound to investigate its effects on cancer cells, as CDK9 is often implicated in the survival and proliferation of malignant cells. By inhibiting CDK9, the compound helps in understanding its role in gene expression and its potential as a therapeutic target for cancer treatment. Additionally, it is used to explore its impact on viral replication, particularly in HIV, where CDK9 is essential for the transcription of the viral genome. This makes CDK9-IN-2 a valuable tool in both oncology and virology research.