CGAS and viral infectious disease: In addition to coordinately regulating ROS response, transcription and metabolism, Zn2+ and Mn2+ together regulate a component of the innate immune system, namely, the cGAS-STING (cyclic GMP-AMP synthase—Stimulator of Interferon Genes) pathway, which is activated by cytoplasmic double-stranded DNA caused by viral infection [162] (Figure 5).