Efficacy evaluation of new Vav1+CISH-/– and YT– Vav1+B2M–/– modified NK cell lines on a 3D glioblastoma tumor spheroids model via assessment of glioblastoma cells viability using fluorescent staining and of their metabolic status using the innovative FLIM method demonstrated the high cytotoxic activity of “enhanced” NK cell lines compared to the unmodified standard line. The gene discussed is VAV1; the disease is neoplasm.