MMP9 and idiopathic interstitial pneumonia: Our enrichment analysis of DEGs in lung tissues from subjects with sarcoidosis also revealed the network of interaction of HBEGF and NAMPT with MMP-9, a well-known matrix metalloproteinase target in IPF that is strongly associated with lung injury and fibrosis (35) and associated in progressive sarcoidosis with pulmonary infiltrates or fibrosis (44).