mitogen activated protein kinase 9; Responds to activation by environmental stress and pro- inflammatory cytokines by phosphorylating a number of transcription factors, primarily components of AP-1 such as c-Jun and ATF2 and thus regulates AP-1 transcriptional activity. In T- cells, JNK1 and JNK2 are required for polarized differentiation of T-helper cells into Th1 cells (423 aa)