Han et al. identify VEGFR2 as a suppressor of cGAMP-STING signaling. Upon cGAMP stimulation, VEGFR2 is phosphorylated and suppresses STING activation via activating and recruiting AKT1. The VEGFR2 inhibitor Ki8751 relieves this repression and activates NF-κB signaling, further amplifying STING responses and the antitumor effect.