On the other hand, the previously reported pro-angiogenic effect of VEGF-B has been mostly found under conditions characterized by tissue/blood vessel degeneration, where no or low level of FGFR1 is present due to cell/tissue death, such as in myocardial infarction or degenerated retina (Supplementary Fig. 17b–f)5,40,41 or blood vessel regression after FGF2 withdrawal.2 Consistently, other groups have also reported that FGFR1 levels are much lower in adult mouse/rat hearts (almost nine folds lower than in embryonic hearts).44,45. Here, FGF2 is linked to myocardial infarction.