MMP9 and non-small cell lung carcinoma: Research has demonstrated that the overexpression of microRNA-520a-3p significantly reduces the ratios of p-AKT/AKT, p-PI3K/PI3K, and Bcl-2/Bax, as well as the levels of mTOR, matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-9 (MMP-9) in NSCLC.