In cancer, mediators known to enhance the expansion of MDSC include interleukin-6 (IL-6), tumor necrosis alpha (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), cyclooxygenase-2 (COX2), prostaglandins, stem-cell factor (SCF), macrophage colony-stimulating factor (M-CSF), vascular-endothelial growth factor (VEGF), IL-1β and IL-17 (Shipp et al., 2016). This evidence concerns the gene PTGS2 and cancer.