MAPK8 and glioblastoma: With respect to JNK and p38 activation in GBM cells, it was recently reported that piperlongumine, an alkaloid with lipophilic properties found in plants of the species Piper longum L., can activate JNK and p-38 MAPKs, leading to apoptosis of U87, LN229 and 8MG-BA GBM cell lines through the accumulation of reactive oxygen species [60].