PARP1 and breast carcinoma: • Dual inhibitors of PARP-1 and PARP-2• Inducing breast cancer-mediated bone metastasis via PARP-2, but not PARP-1, definitely in the myeloid lineage, but not in the tumor cells• Inducing differentiation of osteoclast and bone loss• Deletion of PARP2 in myeloid cells increases the frequency of immature myeloid cells in BM, impairing the expression of CCL3 by upregulating the β-catenin-mediated CCL3 transcriptional suppression• Impaired CCL3 expression by changing subpopulations of T cell led to the creation of an immunosuppressive environment