CD40 and diabetes mellitus: The upregulation of CD40 in endothelial cells, macrophages and T cells in diabetes suggested that enhanced CD40 expression could play a key role in mediating leukocyte adhesion through the CD40-CD40L signaling pathway, resulting in the induction of pro-inflammatory and pro-thrombotic processes (Libby and Simon, 2001; Lutgens et al., 2007).