ID1 and neoplasm: The results showed that bone marrow cells primed by Id1-overexpressing tumour in ‘donor' mice, when mixed with the EC9706 cells and subcutaneously injected into the flank of nude mice, had the highest propensity to induce spontaneous metastasis (two out of five mice had spontaneous metastasis in the lungs) compared with the control group (none of five mice had spontaneous metastasis in lung) and that MF-1 treatment abolished this effect (no lung metastasis detected in the group) (Fig. 7d).