CGAS and familial dilated cardiomyopathy: In parallel with the heightened levels of cytoplasmic mtDNA in the hearts of DCM mice, we next identified the key cytosolic dsDNA sensor and found that the cGAS-STING signaling pathway was activated as indicated by upregulated content of cGAMP in the hearts of DCM mice [31] (Fig. 1d), accompanied with the increased protein level of cGAS, phosphorylation of TANK-binding kinase 1 (TBK1) and type-I interferon (IFN) regulatory factor 3 (IRF3) in DCM mouse hearts compared with control mouse hearts, while the expression of STING showed no significant change (Fig. 1e).