CXCR4 and breast cancer: A significant decrease in the number of adhesive cells in the CXCR4-shRNA transfection group was observed when compared with the negative and blank control groups (P<0.05); however, no significant difference was identified between the negative and blank control groups (P>0.05), which indicated that breast cancer cells may be inhibited by the downregulation of the CXCR4 gene in vitro (Table II).