MDSC-derived S100A8/A9 significantly elevates the release of human matrix metalloproteinases from cancer cells to catabolize the ECM (Hu et al., 2021), increasing the invasiveness of proliferative BC tumors (Brisson et al., 2015) and causing widespread recurrence and metastasis (Di Martino et al., 2022). The gene discussed is S100A8; the disease is cancer.