Fig 1: Helios+ Tregs promote angiogenesis through the VEGFA/VEGFR2 pathway in a mouse model of acute lymphoblastic leukemia. (A) Western blot and quantitative analyses of VEGFA, VEGFR2 and p-VEGFR2 proteins in the BM of the blank, model, Helioshigh and Helioslow groups. (B) Quantitative analyses of the CD31 MVD values of the BM in the blank, model, Helioslow and Helioshigh groups. (C) Quantitation of the mRNA expression of CCL22 in the BM of the blank, model, Helioslow and Helioshigh groups. (D) Quantitation of the protein levels of CCL22 in the plasma of the blank, model, Helioslow and Helioshigh groups. (***P<0.0005, **P<0.005, *P<0.05). VEGF, vascular endothelial growth factor; VEGFR2, VEGF receptor 2; p-VEGFR2, phosphorylated VEGFR2; MVD, microvascular density; BM, bone marrow; CCL2, CC-chemokine ligand 22.