Amphiregulin (AREG), one of the ligands of epidermal growth factor receptor (EGFR) 3, has been observed in malignant astrocytoma 4–6 and is responsible for activating complex pathway networks, including Ras/MAPK, PI3K/Akt, PLC γ, and stat. Here, AREG is linked to astrocytoma (excluding glioblastoma).