Among the upregulated type I IFN-related genes, MX1, which has a specific antiviral action against many viral infections, was identified as a potential marker to predict the immune persistence of the EV71 vaccine, since its expression level in the recall response was strongly correlated with the levels of the titers of EV71 neutralizing antibody at 180 days post-vaccination [23]. This evidence concerns the gene MX1 and viral infectious disease.