Notably, PMN‐MDSCs can produce various pro‐angiogenic factors that stimulate tumour angiogenesis, such as Bv8, matrix metalloproteinase 9 and vascular endothelial growth factor A. Moreover, neutrophil extracellular traps released under conditions such as hypoxia, complement or fatty acid stimulation can induce dormant cancer cell division and trap circulating tumour cells to promote formation of premetastatic niche.6, 7. This evidence concerns the gene MMP9 and neoplasm.