In PCa bone metastasis, ac-KLF5 (acetylated KLF5) up-regulates CXCR4 expression through histone acetylation in the promoter region of CXCR4 gene, and further promotes IL-11 secretion, osteoclast differentiation and the regulation of tumor cell plasticity. This evidence concerns the gene CXCR4 and posterior cortical atrophy.