MUC5AC and respiratory system disorder: CLCA1 as a regulator of Ca2+-activated chloride ion transport on epithelial cells, mucin expression from goblet cells, cytokine and chemokine expression from monocytes and macrophages, tumor cell migration and metastasis, and proliferation of lymphatic ECs, it has been tested in respiratory diseases, gastrointestinal diseases, cancers, and lymphatic tissue remodeling in humans and experimental models (Table 1).