KDR and cancer: Although we did not observe an effect of VEGFR TK inhibition on PBDCprecursors and subsets in cancer patients, the frequencies of accumulated MSCstended to decrease after AZD2171 treatment.This CD14+HLA-DRneg/low MSC population may be the human equivalent of CD11b+ and Gr-1myeloid suppressive cells identified in mice [32, 33], and we hypothesized thattumor-derived VEGF might have skewed the hematopoiesis towards an expansion ofthese myeloid cells with immunosuppressive traits.