FLT1 and choroidal neovascularization: The putative antiangiogenic effect of IL-4 is also strengthened by the fact that IL-4 can induce an efficient VEGFA-neutralizing agent soluble VEGFR1 (Fms Related Receptor Tyrosine Kinase 1, FLT1) expression in macrophages, and the VEGFA-induced endothelial cell proliferation in vitro and laser-induced choroidal neovascularization in vivo are attenuated by IL-4-polarized macrophages in a sFLT1-dependent manner (29).