TRPM4 and chronic obstructive pulmonary disease: TRPM4 contribution to cardiac conduction as well as the development of arrhythmias has been demonstrated using different approaches, such as channel inhibition with 9-phenantrol, a blocker for TRPM4 (Grand et al., 2008), using TRPM4-deficient mouse models, and by the identification of TRPM4 mutants detected in a variety of inherited human cardiac arrhythmias (Freichel et al., 2017).