ANGPT1 and diabetes mellitus: The disturbed process of angiogenesis which relies on a variety of signaling pathways may play a major role, since it has been shown that elevated Angiopoietin-2 (Ang-2) with declined Angiopoietin-1 (Ang-1) expression (Cui et al., 2011; Ye et al., 2011) and decreased vascular endothelial growth factor (VEGF) with increased angiostatin signaling (Zhu et al., 2010) are involved in dysfunctional cerebral neovascularization in diabetes.