For instance, in murine models of colon adenocarcinoma, melanoma or acute myeloid leukaemia transfection of cancer cells with genes to overexpress G-CSF or GM-CSF results in reduced tumorigenicity (Colombo et al, 1991; Armstrong et al, 1996; Dunussi-Joannopoulos et al, 1998). The gene discussed is CSF2; the disease is acute myeloid leukemia.