MX1 and hand, foot and mouth disease: Polymorphisms of type I IFN stimulated genes were associated with the susceptibility and clinical phenotypes of EV71 HFMD, such as −123 A and −88 T of MX1 obviously reduce the susceptibility of EV71, but individuals with the −123 A or −88 T had a higher MX1 mRNA levels in IFN-β stimulated PBMC compared with non-carriers18.