It was found that all autofluorescence decay parameters of NAD(P)H coenzyme in human glioblastoma cells significantly change when exposed to YT-Vav1+CISH–/– and YT–Vav1+B2M–/– modified NK cells; this indicates that tumor cell metabolic status is changed and is consistent with data on spheroid dead cells fraction increase and living cells fraction decrease and, accordingly, on effective response to therapeutic effects. The gene discussed is B2M; the disease is glioblastoma.