YKL-5-124 is primarily utilized in research settings as a potent and selective inhibitor of cyclin-dependent kinase 7 (CDK7). Its application is significant in the study of cell cycle regulation and transcription processes, as CDK7 plays a crucial role in both. Researchers employ YKL-5-124 to investigate the effects of CDK7 inhibition on cancer cell proliferation, as CDK7 is often overactive in various cancers. By blocking CDK7, this compound helps in understanding the mechanisms of tumor growth and identifying potential therapeutic targets. Additionally, YKL-5-124 is used to explore its impact on RNA polymerase II-mediated transcription, providing insights into gene expression control. Its specificity makes it a valuable tool for dissecting the complex roles of CDK7 in cellular processes and for developing targeted cancer therapies.