c-Jun N-terminal kinases (JNKs) are members of the MAPK family that play a role in T-cell differentiation and apoptosis in response to stress stimuli. There are ten JNK isoforms derived from three different genes (JNK1, JNK2, and JNK 3). JNK1 and JNK2 can be found in cells throughout the body, while JNK3 is primarily found in the brain. Inhibition of JNK is seen as a potential target for treatment of cancer, neurodegenerative diseases, inflammatory disorders, and insulin resistance. There are a number of small-molecule inhibitors currently available that act on JNK, though pinning down inhibitors with higher specificity and potency remains an active area of research for pharmaceutical companies.