To identify and characterize the BMDC subpopulations that were influenced by Id1-overexpressing tumour xenografts, subpopulations of BMDCs that are known to contribute to tumorigenesis5, identified by different cell-surface antigens including CD11b, F4/80, CD335, Gr-1, Tie-2, VEGFR1 and VEGFR2, were analysed. This evidence concerns the gene ID1 and neoplasm.