MMP9 and breast cancer: IL-19 increases the expression level of all the factors like CXCR4, interleukin-6, TGF-β, IL-1β, MMP-2, MMP-9, and fibronectins that promote tumor development, migration of BC cells and is also linked with metastasis in breast cancer (Fig. 1) (Méndez-García et al., 2019).