In the laser-scanning confocal microscopy on the glomeruli of type I and type II diabetic mice, the TLR2-expressing area coincided with the VE-cadherin and PECAM-1-double positive areas, suggesting that the TLR2-expressing cells in the glomeruli with diabetic nephropathy were mainly glomerular endothelial cells (Fig. 3, 4). Here, PECAM1 is linked to diabetic kidney disease.