(A) resected zebrafish treated with vehicle, representative image, (B) resected zebrafish treated with PMX205, representative image, cardiomyocyte marker tropomyosin (red), PCNA (green), cardiomyocyte nuclei (MEF2, blue); scale bar - 50µm (C) quantification of proliferating cardiomyocytes in vehicle and PMX205 treated hearts of zebrafish, * p<0.01, n=5 (vehicle), 8 (PMX205).