The highest level of mRNA was observed for HDAC9a and HDAC9b, with relative expression reaching values above 100 for normal brain tissue and grade I astrocytomas; however, HDAC6 and HDAC7 showed levels of expression comparable with those of class I (approximately 1.0 and 3.0). This evidence concerns the gene HDAC6 and astrocytoma (excluding glioblastoma).