GSK-J4 Hydrochloride is primarily utilized in research settings to study its role as an inhibitor of histone demethylases, specifically targeting the KDM6 subfamily, which includes enzymes like UTX and JMJD3. By inhibiting these enzymes, it helps in understanding the regulation of gene expression, particularly in the context of development and disease. This compound is particularly valuable in cancer research, where it is used to explore the mechanisms of tumor suppression and the potential for therapeutic intervention. Additionally, it aids in the study of immune system regulation and inflammatory responses, providing insights into autoimmune diseases and potential treatment strategies. Its application extends to neuroscience research, where it helps in understanding the epigenetic mechanisms underlying neural development and neurodegenerative disorders.