TYK2 and experimental autoimmune encephalomyelitis: However, our data are in agreement with the fact that primary human immune cells carrying the MS-protective TYK2 variant rs34536443 (Pro1104Ala) have a reduced response to IFN-β stimulation [51, 52] and that mice homozygous for the corresponding mutation (Pro1124Ala) are completely protected from developing the animal model of MS, experimental autoimmune encephalomyelitis (EAE) [52].