In this work, we have developed the methodological approach consisting in glioma modelling and performing IVM in transgenic C57Bl/6-FoxP3-eGFP mice, which can be used in future studies to find the ways to overcome the immunosuppressive tumor microenvironment, including suppression of Tregs activity and conversion of glioma from immunologically “cold” to “hot” state, a condition in which anti-tumor immune response in glioblastoma will become more effective. The gene discussed is FOXP3; the disease is glioma.