KCNJ5 and familial dilated cardiomyopathy: As this functional category has yet to be characterized in DCM, we focused on 7 of these ion channels (SCN2B, KCNJ5, KCNJ8, CLIC2, CLCN3, CACNB2, and CACNA1C) in this study, based on the described relationship of these channels with the contraction process (Table 2).