Ultramutated CRCs have exonuclease domain mutations in POLE,1, 2, 8 and tumors with these mutations harbor a characteristic nucleotide substitution spectrum with a high frequency of C‐to‐A transversions.1, 7 Previous studies have shown that patients with endometrial cancer (EC) and glioblastoma harboring pathogenic exonuclease domain mutations in the POLE gene exhibit better prognosis,9, 10 suggesting that these mutations may be promising prognostic biomarkers. Here, POLE is linked to glioblastoma.