EGFR and central nervous system cancer: p38 also regulates ubiquitin-mediated degradation of stemness factors in glioma CSCs, as activation of the p38 pathway leads to reduced epidermal growth factor receptor (EGFR) surface expression via ubiquitin ligase-mediated degradation of EGFR, thereby attenuating the sphere-forming and self-renewal capacities of the CSCs [72].