In addition, expression of many genes related to the functions of extracellular matrix formation (MMP7, TIMP1 and LAMA5) and growth factors (MDK, SPP1 and C3) were significantly up-regulated in the SCGB3A2high club cells in IPF (Fig 4B and 4C). This evidence concerns the gene SPP1 and idiopathic pulmonary fibrosis.