MAPK8 and central nervous system cancer: For example, JNK1, but not JNK2, has been reported to be required for lymphoblast transformation by BCR-ABL [102] and carcinogen-induced hepatocellular carcinoma [103], while some studies implicated JNK2 as the primary isoform involved in glioma cell proliferation [98] and others indicated both JNK1 and JNK2 contribute to maintaining self-renewal and tumorigenicity of glioma CSCs [95,97].