The tumor weight and volume of mice in the CELF1-KO group decreased significantly compared with those in the control group, and the expression of the cell proliferation indicator Ki-67 also decreased; we also found that CELF1-KO combined with the GLUT1 inhibitor BAY876 inhibits the proliferation of breast cancer cells in vivo in the subcutaneous tumor implantation experiment in nude mice (Figures 7A–E). This evidence concerns the gene CELF1 and breast cancer.