MAPK3 and meningioma: The MAPK–ERK and the AKT pathways are known to be active in meningioma and to influence tumor progression.30 After STAT1-KD, both AKT and ERK1/2 showed a 95% and 80% reduction in protein phosphorylation, respectively (Figure 3G and H), supporting a critical involvement of STAT1 in the activation of pro-proliferative pathways.