TYK2 and infection: The dependence of in vivo IL-12 responses on TYK2 is clear in Tyk2−/− mouse models of infection, inflammation and cancer, in Tyk2P1124A mouse models of inflammation ([61,79,82] and see below) and in patients with inherited LOF TYK2, who suffer from increased microbial infections and skin inflammation ([43,81] and see Table 2).