Of these enzymes, SQS is increased in invasive lung cancer cells and in the tumor regions of lung cancer specimens, and significantly associated with metastasis and poor prognosis by enhancing NF-κB-mediated up-regulation of matrix metallopeptidase-1 (117) or modulating extracellular signal-regulated kinase (ERK) signaling (120). Here, MMP1 is linked to lung carcinoma.