IFNG and COVID-19: Additionally, while the cytokine and chemokine responses observed in our model are similar to those reported in other humanized mouse models [37,44,68] and many cytokines and chemokines associated with COVID-19 in humans were upregulated including IL1RN, CCL7, IFN-γ, IFNα2 and CXCL9-11 [69,70], others were absent such as IL-6 and TNFα.