My main interest is the diverse clonal structure of CNS tumors, with particular emphasis on glioblastoma. I examine them both retrospectively and prospectively in cooperation with the Clinic and the Department of Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin. My prospective studies are focused on the development of a dedicated chick embryo model that allows to differentiate cancer cells due to phenotypic features such as the ability to migrate or the expression of antigens characteristic for cancer stem cells. In retrospective studies, I focus primarily on changes in the proportion of cells with specific phenotypes in rare cases of glioblastoma. The ultimate goal of my research is a detailed description of the various clones in glioblastoma to develop effective anticancer therapies.