Results from previous studies have suggested that (1) MMP1 could regulate the mechanisms of LUAD cell proliferation, migration, and invasion under the regulation of mir-202-3p [54], (2) p53 dysfunction caused by XPC gene (xeroderma pigmentosum) deficiency in lung cancer may enhance tumor metastasis by increasing MMP1 expression [55], (3) macrophage-specific inhibition of MMP1 secretion may be a potential therapy to reduce lung metastasis in smoking cancer patients [56]. The gene discussed is MMP1; the disease is cancer.