MAPK3 and brain cancer: SFN is known to have anti-proliferative properties on brain cancer cells in vitro, by at least three signaling pathways: namely, induced nuclear factor erythroid 2-related factor 2 (Nrf2), activated extracellular signal-regulated kinase 1/2 (ERK1/2), and down-regulated matrix metallopeptidase 2 (MMP2) and Cluster of Differentiation 44 protein (CD44v6) [8].