Among others, the following polymorphisms of genes are reported to be associated with increased frequencies in patients with sporadic IPF: genes encoding for cytokines, such as IL-1 a, tumor necrosis factor-α, lymphotoxin α, IL-4, IL-6, IL-8, IL-10, IL-12, and TGF-ß1 [113–123], α 1 antitrypsin and angiotensin-converting enzymes [116, 124], profibrotic molecules (TGF-β1), coagulation pathway genes (plasminogen activator inhibitors-1 and -2 and surfactant proteins-A and -B) [125], and MMP-1 [126] polymorphisms, have been reported to have increased frequencies in patients with sporadic IPF. Here, IL4 is linked to idiopathic pulmonary fibrosis.