MMP9 and idiopathic pulmonary fibrosis: Among the novel, commonly identified deregulated genes in IPF was Lipocalin-2 (LCN2), also known as neutrophil gelatinase B-associated lipocalin (NGAL), as it was initially identified in neutrophilic granules in association with matrix metalloproteinase 9 (MMP9; gelatinase B) (7, 8).