PECAM1 and Hyperglycemia: In line with the Hhip expression reported in endothelial cells11, our co-localization experiments (Fig. 2a, immunofluorescence (IF)) showed that hyperglycemia-induced Hhip and TGFβ1-IF expression was predominantly found in GECs (revealed by CD31 co-localization), suggesting that GECs might be the potential source of elevated Hhip expression in diabetic glomeruli.