FGF2 and neoplasm: In order to validate that human growth factors are capable of inducing embryonic zebrafish neo-vessel formation we injected recombinant human VEGFA, FGF-2 or PDGF-BB into the yolk of zebrafish embryos at 50 hpf (mirroring the time when tumour cells would be injected) and quantified neo-vessel and SIV lengths after 70hrs (Supplementary Figure 10).