In an in vitro study with human lung mucoepidermoid carcinoma (NCI-H292) cells, the levels of MUC5AC (a mucin protein) were quantified, and it was observed that Rg5 reduced the secretion of MUC5AC, as well as the levels of MUC5AC mRNA. The gene discussed is MUC5AC; the disease is pulmonary mucoepidermoid carcinoma.