Among our included studies, three reported a small proportion of IDH-mutant cases (<10%) in GBM patients with EGFR amplification or the EGFRvIII mutation: Lv 2012 [31]: of 35 patients with EGFR amplification, 1 of 11 EGFRvIII-positive and 5 of 24 EGFRvIII-negative patients had IDH mutations; Weller, 2014 [43]: all the EGFRvIII-positive patients were IDH-wildtype, but 9% of the EGFRvIII-negative patients had IDH mutations; Sepúlveda-Sánchez 2017 [38]: among 19 EGFRvIII-positive patients, 2 had IDH mutations, while none of the 30 EGFRvIII-negative patients had IDH mutations. Here, IDH1 is linked to glioblastoma.