In the type 2 diabetes mellitus (T2DM) neuropathy rats, the expressions of fibrinogen (FIB), glial fibrillary acidic protein (GFAP) and ionised calcium-binding adaptor molecule-1 (IBA1) were upregulated, while the expressions of platelet/endothelial cell adhesion molecule-1 (CD31) and B-cell lymphoma 2 (Bcl-2) were downregulated. Here, PECAM1 is linked to diabetes mellitus.