Calcium-activated chloride channel (transmembrane protein 16A, TMEM16A) and calcium-activated chloride channel regulator 1 (CLCA1, the human ortholog of mouse CLCA3/Gob-5) have both been linked to mucus hypersecretion in asthma and COPD (Brett, 2015). Here, CLCA1 is linked to chronic obstructive pulmonary disease.