HDAC9 and glioma: Overexpressed HDAC1 in glioma positively altered its expression with glioma grade, IDH1 wildtype, and 1p/19q non-codeletion, while HDAC11 was downregulated and acted oppositely compared to HDAC1. The majority of the HDAC family significantly correlated with the grade, IDH1 mutation, and 1p/19q codeletion in glioma.