CTNND1 and neoplasm: Mechanistically, downregulation of catenin delta 1 (CTNND1) in metastatic bone lesions promoted tumor recruitment to bone by upregulating CXCL12/CXCR4 axis via PI3K/AKT/HIF-1α pathway, while recruitment of neutrophils in the bone was stimulated by secretion of GM-CSF and IL-8.