To further clarify the mechanism by which cfDNA contributed to inflammation in OLP, three siRNAs were designed to knock down STING in THP-1 macrophages, and western blotting results showed that the protein levels of the STING and p-STING were significantly decreased by siRNAs (Figure 3C), among which, siRNA-STING2 that showed the best inhibitory effects was selected for the subsequent experiments. Here, STING1 is linked to oral lichen planus.