UNLABELLED: One of the alternative approaches to glioblastoma treatment is cellular immunotherapy based on natural killer cells (NK cells). To enhance their cytotoxic effect on tumor cells, new NK cell lines are being created using genetic engineering techniques. MATERIALS AND METHODS: The study used a primary culture of GBM7-Luc2-mKate2 human glioblastoma, a line of YT (YTwt) wildtype human NK cells, as well as lines created by us with overexpression of VAV1 protein with either RESULTS: It was found that autofluorescence attenuation parameters of NAD(P)H coenzyme in human glioblastoma cells change significantly when exposed to both YT-Vav1 CONCLUSION: The data obtained on enhanced cytotoxic activity of new modified NK cell lines against human glioblastoma spheroids are important to understand interaction mechanisms between tumor and immune cells and the development of glioblastoma adoptive cell therapy.