MAPK9 and glioblastoma: The protein encoded by mitogen-activated protein kinase 9 (MAPK9), also known as c-Jun N-terminal kinase 2 (JNK2), is involved in regulating various cellular processes, including cell growth, transformation, and apoptosis.28 This pathway can also be activated by growth factors, such as epidermal growth factor and platelet-derived growth factor.29–31 Targeted inhibition of MAPK9 with specific antisense oligonucleotides resulted in marked growth suppression in human GBM T98 cells, suggesting that MAPK9 inhibition could have therapeutic benefit.32