FLT4 and congestive heart failure: A significant (19.6% for VEGFC, 38.8% for LYVE1 and 21.7% for FLT4 on average) reduction was observed for lymphatic markers VEGFC, LYVE1, and FLT4, and a 31.6% reduction was observed in PDPN (p=0.07) in hearts from chronic heart failure patients compared with hearts from healthy donors (Figure 1A–D, Figure 1—source data 1), suggesting that the cardiac lymphatic vasculature is impaired in human chronic heart failure.