During viral infection, viral RNA can be recognized by cytoplasmic cellular pattern-recognition receptors, such as the retinoic acid-inducible gene 1 protein (RIG-I, DDX58) and melanoma differentiation-associated protein 5 (MDA5), and activate mitochondrial antiviral signaling protein (MAVS) to induce antiviral and pro-inflammatory factors. This evidence concerns the gene IFIH1 and viral infectious disease.