ANGPT1 and sickle cell disease: There are findings demonstrating that another pro-angiogenic factor, angiopoietin-1 displaying potent pro-angiogenic activity, and significantly increasing endothelial cell proliferation, migration and capillary-like structure formation, is present in elevated concentrations in patients with steady-state sickle cell anemia (Duits et al., 2006; Lopes et al., 2015).