Compared with controls, serum concentrations of OPN in AE-IPF patients increased obviously than in patients with S-IPF (5.24 [3.09, 9.11] versus 2.93 [2.05, 4.85] ng/ml, p=0.003) or healthy controls (0.71 [0.33, 1.55] ng/ml, p < 0.001) (Figure 1(a)). The gene discussed is SPP1; the disease is idiopathic pulmonary fibrosis.