The index of total periostin/monomeric periostin was significantly lower in IPF patients (2.1, n = 40) than in either AD (14.2, n = 224), SSc (11.7, n = 37), or bronchial asthma (7.3, n = 143) patients (Fig 6). The gene discussed is POSTN; the disease is idiopathic interstitial pneumonia.