Interestingly, FACS analysis of harvested tumor cells (CD326+ HCT116) did not display any induction of surface expression of CXCR4 in doxycycline group as compared to control (Fig. 6J) again suggesting that the promotion of tumor growth was due to the overexpression of intracellular CXCR4 protein. This evidence concerns the gene CXCR4 and neoplasm.