2,3-cGAMP is an endogenous cyclic dinucleotide (CDN) produced by cGAS (cGAMP synthase) in response to double-stranded DNA in the cytoplasm. It acts as a STING activator and ligand, inducing interferons (IFNs) via the TBK1/IRF3 pathway and pro-inflammatory factors via the NF-kappaB pathway.