Indeed, in high-grade breast cancers containing high amounts of SPARC, the deposition of abundant collagen bundles induces the COX-2–dependent expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) in tumor cells attracting CD33+ myeloid-derived suppressor cells responsible for cancer cell EMT and chemoresistance81. Here, IL6 is linked to breast cancer.