JQ-1 is primarily used in biomedical research as a potent and selective inhibitor of the BET (bromodomain and extra-terminal) family of proteins, particularly BRD4. By binding to the bromodomain of these proteins, JQ-1 disrupts their interaction with acetylated histones, thereby modulating gene transcription. This mechanism has made it a valuable tool in studying cancers, especially those driven by dysregulated gene expression such as leukemia, multiple myeloma, and solid tumors. It has shown promise in preclinical models by suppressing tumor growth and inducing apoptosis.

In addition to oncology, JQ-1 is used to investigate inflammatory diseases, cardiovascular conditions, and viral infections such as HIV, where BET proteins play a role in viral latency and replication. It is also employed in epigenetic research to understand chromatin regulation and transcriptional control. Due to its ability to cross cell membranes easily, JQ-1 is widely used in cellular and animal models, though it is not approved for clinical use in humans. Its derivative compounds are being explored in drug development for targeted therapies.