MAPK4 and central nervous system cancer: To identify the underlying mechanism that circ-MAPK4 inhibits apoptosis in glioma cells, we focused on the Mitogen Activated Protein Kinase (MAPK) signaling pathway including p38 kinases, c-Jun amino-terminal kinases (JNKs), and signal-regulated kinases (ERKs), which are crucial molecules involved in cancer pathogenesis.