Guidelines published in the cIMPACT-NOW update 3 states that EGFR amplification qualifying for Grade 4 designation of IDH-wildtype astrocytoma in the absence of high-grade histologic features should only be called in the presence of “high-level copy number gains” as established by “clinically validated assays” [9]. The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).