Injection of the IL-12-transduced tumour cells into IFN-γ-deficient mice resulted in tumours that grew with kinetics similar to the parental tumours (data not shown), and the vessel morphology was similar (although not identical) to that of the vessels in the parental tumour and the vessels expressed the VEGFR-3 (data not shown). The gene discussed is FLT4; the disease is neoplasm.