The goal of this project is to identify interacting proteins of Flag-tagged STING before and after cGAMP stimulation. STING knockout (STING-KO) BJ cells stably re-expressing Flag-STING were treated with 1 M cGAMP and whole cell lysates were harvested 30 min later for IP with anti-Flag M2 affinity gel. STING-KO cells without Flag-STING expression were used as a negative control.