The PROTAC CDK9 degrader-4 is primarily utilized in the field of targeted protein degradation, specifically for research and therapeutic purposes. It is designed to selectively degrade cyclin-dependent kinase 9 (CDK9), a protein involved in transcriptional regulation and cell cycle progression. By degrading CDK9, this compound helps in studying the role of CDK9 in various cellular processes, including cancer cell proliferation and survival. It is particularly valuable in preclinical studies for exploring potential treatments for cancers where CDK9 activity is dysregulated. Additionally, it serves as a tool for understanding the mechanisms of PROTAC technology, which is an emerging approach in drug discovery for degrading disease-causing proteins.