A number of studies have reported a positive correlation between fibrosis and neutrophils in CRS, probably because neutrophils are the primary source of TGF-β2-positive cells that can positively correlate with the myofibroblast number and fibronectin expression levels (100), i.e., the number of neutrophils which can positively correlate with the expression of pro-fibrotic factors, thus suggesting that neutrophils likely promote CRS via TGF-β2 in tissue fibrosis. This evidence concerns the gene TGFB2 and fibrosis.