CACNB2 and familial dilated cardiomyopathy: The downregulation of KCNJ5 and KCNJ8 impairs the K+ current; and the downregulation of CACNB2 and CLIC2 leads to an increase in cytoplasmic Ca2+ ions, suggesting an altered time course for myocyte shortening and relaxation in DCM and a compromise in cardiac contractibility.