CGAS and viral infectious disease: For example, cGAS is phosphorylated by AKT at S305 after being activated for a while, leading to a suppressed enzymatic activity.98 Nitro-fatty acids synthesised endogenously in response to viral infection covalently modify STING and inhibit its palmitoylation, and thus activation.99 In addition to adding negative PTMs, the removal of positive PTMs represents a way to restrict the cGAS-STING signalling.