To further confirm whether Ac-KLF5 is essential for the synergistic effect of docetaxel and AMD3100 on bone metastasis of PCa cells, we administered the CXCR4 inhibitor AMD3100 to mice carrying tibial tumors of KLF5KQ or KLF5KR, with or without docetaxel treatment, and analyzed metastatic tumor growth by measuring alleviated bone lesions with X-ray radiographs (Supplementary Fig. 9c) and tumor areas (Fig. 8d, e). This evidence concerns the gene KLF5 and neoplasm.