In 2020, Appay et al (8) reported that CDKN2A HD was seen in 7% (33/483) of grade 3 oligodendrogliomas, similar to our result, and CDKN2A HD in oligodendroglial tumors was associated with shorter overall survival independent of necrosis and MVP. This evidence concerns the gene CDKN2A and oligodendroglioma.