TNF and idiopathic pulmonary fibrosis: Other studies in sporadic IPF patient cohorts have identified polymorphisms in genes encoding cytokines IL-1 α, TNFα, lymphotoxin α, IL-4, IL-6, IL-8, IL-10, and IL-12 enzymes (α1-antitrypsin and angiotensin-converting enzyme) [198,199,200], profibrotic molecules TGFB1, coagulation pathway genes PAI1 and PAI2, genes for surfactant proteins A and B, immunomodulatory NOD2/CARD15, and matrix metalloproteinase MMP1 in association with increased risk of IPF.