SAM analysis showed that the genes with increased expression in IPF compared to NSIP were involved in epithelial-to-mesenchymal transition (insulin growth factor binding protein-5 [IGFBP-5], Prominin-1), myofibroblast differentiation and proliferation (smooth muscle alpha-actin [ACTA-2], OPN), collagen deposition (OPN, IGFBP-5, POSTN), matrix remodeling (MMP-1, MMP-7, ACTA-2) peripheral blood mononuclear cells (PBMCs) proliferation and infiltration (IGFBP-5, MMP-7) and senescence (IGFBP-5, OPN, MMP-2). The gene discussed is ACTA2; the disease is idiopathic interstitial pneumonia.