PDGFB and vascular malformation: Specifically, we assessed the proportion of ciliated endothelial cells in neonatal retinas from Pdgfb-CreERT2;Pik3caH1047R mice which heterozygously express Pik3caH1047R in endothelial cells following 4-hydroxytamoxifen-induced recombination at postnatal day 1 (P1) and exhibit vascular malformations by P645.