PTGS2 and idiopathic pulmonary fibrosis: Xaubet et al. demonstrated that the carriage of double homozygote (GG/CC) at the single nucleotide polymorphism loci of COX2.3050 and COX2.8473 polymorphisms did not increase disease progression but may increase the susceptibility to IPF by approximately 1.4 fold at age 30 and by a smaller fold greater than 1 up to age 66 years [128].