VEGFA and cancer: Angiogenesis, the process of new bloodvessel formation, is a criticalfactor in cancer progression and is primarily regulated by the vascularendothelial growth factor (VEGF). The promoter region of VEGF contains guanine-richsequences capable of forming DNA G-quadruplexes (G4s). G4s are secondary structures composed of stacked guaninetetrads stabilized by Hoogsteen hydrogen bonding and monovalent cationssuch as K+ or Na+.