ICAM1 and diabetes mellitus: At the same time, DPP4 inhibitors induced amelioration of different vascular features, including diabetes-induced changes in the subcellular distribution of the tight junction proteins occludin, claudin-5, and zonula occludens-1; BRB breakdown; ICAM-1 upregulation; pericyte loss; and formation of acellular capillaries (Goncalves et al., 2012, 2014; Dietrich et al., 2016; Hernandez et al., 2017).