Used in research as a selective inhibitor of CDK12/CDK13 kinases, THZ531 helps study transcription regulation in cancer cells. It shows potential in disrupting the growth of certain tumor types by inducing DNA damage and apoptosis. Commonly applied in preclinical studies to evaluate the effects of transcriptional CDK inhibition, particularly in breast and ovarian cancer models. Its high selectivity makes it a valuable tool for probing the biological roles of CDK12 and CDK13 without broadly affecting other kinases.