In order to address the role of inducible expression of NAMPT in an in vivo cancer setting, mice bearing the homozygous NRE1 floxed allele with the broad hematopoietic lineage-specific deletion driver Vav-Cre, or their NRE1 floxed littermates lacking Cre, were inoculated subcutaneously with B16F10-ova melanoma cells33 to form flank tumors. This evidence concerns the gene VAV1 and cancer.