Both genetic and epigenetic changes underlite the mechanisms of tumor initiation and progression. In the present study we analyze sox2 gene expression and its epigenetic regulation in primary cultures of malignant gliomas. The sox2 expression was detected in the vast majority (74%) of the investigated gliomas and absent in morphologically normal brain tissue. This indicates the process of glioma malignant transformation. We have also shown that the association of different areas of the sox2 gene with important epigenetic markers, posttranslational modifications of H3 histone H3K4ac and H3K9met3, does not correlate with the sox2 expression. However, this may indicate the stochastic nature of the regulation of sox2 gene expression in malignant gliomas.