C1QTNF1 and type 2 diabetes mellitus: Although elevated serum CTRP1 level is thought to be, in part, related to more profuse adipose tissue depot in type 2 diabetic patients with low coronary collateralization, further in vitro experiments which determine the effects of CTRP1 on angiogenic property of endothelial progenitor cells derived from culture of peripheral blood mononuclear cells showed that recombinant human CTRP1 protein decreased VEGFR-2 not VEGF and VEGFR-1 expression in a concentration -dependent manner in these cells.