Since derived primary glioma cultures significantly differed in their sensitivity to TMZ as well as in expression profiles of examined glioma and hypoxia-related markers, verification experiments were carried out on stabilized cell lines U87MG and its STAT3 knockout variant U87MG-STAT3KO prepared by the CRISPR / Cas methodology (Supplementary Fig. 1). The gene discussed is STAT3; the disease is glioma.