Recent studies have demonstrated that IRF9 plays an important role in the development of cancer, and in breast cancer, IRF9 overexpression confers resistance to antimicrobial agents.[25] In neuroblastoma (NB), polypyrimidine tract binding protein 2 (PTBP2) induces alternative splicing of IRF9 within the exon 6‐7‐8 region, leading to tumor‐associated monocyte/macrophage chemotaxis and repolarization[44] In the present study, we found that IRF9 regulates CCL5 mRNA expression and secretion and is regulated by ITGβ8/PI3K/AKT pathway. This evidence concerns the gene PTBP2 and breast cancer.