In order to check for potential gender differences, the data presented in Fig. 1C are displayed separately with respect to the sex of the animals used for cardiomyocyte isolation (Figs. 1D and 1E). In Fig. 1D the potassium current densities from wt and dystrophic (mdx and mdx-utr) cardiomyocytes derived from female mice only are compared. In Fig. 1E the respective current density data (wt and mdx) from only male mice are presented. Our data imply that dystrophin-deficiency significantly decreased the IK1 densities, irrespective of the gender of the animals used for cardiomyocyte isolation.