HDAC2 and glioma: The OS analysis based on GEPIA revealed that the glioma patients with high expression levels of HDAC1 (HR:3.9, p < 0.0001), HDAC2 (HR:1.3, p = 0.024), HDAC3 (HR:4.4, p < 0.0001), and HDAC7 (HR:3.3, p < 0.0001) would face with more risks compared to the ones with low expression of these genes (Figures 5A,B).