IGF1R and meningioma: In keeping with previous reports, the anaplastic tumors demonstrated marked upregulation of major growth factor receptor and kinase circuits implicated in meningioma pathogenesis, notably epidermal growth factor receptor (EGFR), insulin-like growth factor (IGFR), vascular endothelial growth factor receptor (VEGFR) and mTOR complex 1 (mTORC1) kinase complex36–41.