Wolfram Doehner1, Kamyar Kalantar-Zadeh2, Stefan D Anker3. 1. Department of Cardiology, Campus Virchow, Center for Stroke Research, Berlin-Brandenburg Center for Regenerative Therapies, Charité Universitätsmedizin Berlin, Berlin, Germany. 2. Division of Nephrology and Hypertension, School of Medicine, University of California, Irvine. 3. Department of Cardiology, Campus Virchow, Berlin-Brandenburg Center for Regenerative Therapies, Charité Universitätsmedizin Berlin, Berlin, Germany.