MMP9 and lung carcinoma: In this study, we investigated the role of NMI in the regulation of cell proliferation, apoptosis, and migration in human lung cancers, and also explored its underlying molecular mechanisms involved in PI3K/AKT, Erk/p38, MMP9/β-cadherin, NF-κB/COX-2/PGE2, and PARP/Bcl-2/Caspase3 signaling pathways.