The DFS-oriented study using GEPIA data showed that more transcripts of HDAC1 (HR:3.0, p < 0.0001), HDAC3 (HR:2.7, p = 2.1e−15), HDAC7 (HR:2.1, p = 3e−09), and HDAC9 (HR:1.5, p = 0.0026) accompanied with less DFS probabilities in glioma patients (Figures 7A–C). This evidence concerns the gene HDAC9 and glioma.