In another research on lung cancer, after A549 (human lung adenocarcinoma cell line) treated with etomidate, the activation of MMP2 was inhibited, and expressions of PKC, MMP7, MMP1, MMP9, and p-p-38 were significantly downregulated, but those of RAS, PI3K, and P-ERK (phosphorylation extracellular signal-regulated kinase) were upregulated; therefore, the migration and invasion of A549 were inhibited (63). Here, MMP9 is linked to lung carcinoma.