Inversely, patients with CRSwNP had a gene mutation associated with cystic fibrosis in 6% [16-18]. Another genetic factor for the genesis of CRSwNP is mentioned in a Polish study that found an increased rate of a -765 G/C polymorphism of cyclooxygenase-2 (OF: 4.04; 95% CI: 2.32-7.03) and a C allele (OR: 3.68; 95% CI: 2.38-5.68) compared to the control group of the same gender and age. Here, PTGS2 is linked to cystic fibrosis.