JAK1 and viral infectious disease: Furthermore, overexpression of NS2B3 markedly reduced the protein levels of Jak1 but not the levels of STAT1, which consequently inhibited the phosphorylation of Jak1 and STAT1 (Figure 3f), as well as the translocation of STAT1 from the cytoplasm to the nucleus after viral infection (Figure 3g; Supplementary Figure S3B).