FLT4 and persistent truncus arteriosus: By measuring the levels of VEGF-C, VEGFR3, and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), using western blots, and examining the colocalization of lymphatic vessels and macrophages, using immunofluorescence, we explored the changes that occurred in the cardiac lymphatic system and the role played by LCZ696 in TAC mice.