TCS JNK 5a is primarily used as a selective inhibitor of c-Jun N-terminal kinase (JNK) in research settings. It is widely applied in cellular and molecular studies to probe the JNK signaling pathway, which plays a key role in apoptosis, inflammation, and stress responses. Due to its selectivity, it helps researchers investigate the involvement of JNK in neurodegenerative diseases, such as Alzheimer's and Parkinson's, as well as in conditions like diabetes and cancer. It is also utilized in drug development to validate JNK as a therapeutic target and to assess the effects of its inhibition on cell survival and inflammatory processes.