CXCL12 and mastitis: Furthermore, experimental evidence demonstrates that exogenous CXCL12 administration induces mastitis pathogenesis in murine models (a system with noted differences from human PCM), characterized by both inflammatory infiltration and interstitial fibrosis, indicating that stromal fibroblast-secreted CXCL12 exacerbates inflammatory responses and promotes epithelial cell EMT via paracrine signaling—a critical pathway for sustained inflammation and progressive fibrotic remodeling in the mammary gland microenvironment.