IGFBP4 and type 1 diabetes mellitus: People with DN have a significant increase in their plasma IGFBP-1 and IGFBP-4 (Al Shawaf et al., 2019), more importantly, IGFBP-4 fragments (including N- and C-terminal fragments (NT-IGFBP-4 and CT-IGFBP-4)) are related to cardiovascular mortality in type 1 diabetes patients no matter with or without nephropathy (Hjortebjerg et al., 2015).