ChIP assays carried out after infection with the recombinant virus demonstrated that, unlike the wild type ZH NSs protein, NSsΔ210–230 protein did not interact with the IFN-β promoter (Figure 6F) whereas the recombinant wild type protein interacted with the promoter as early as 4 h p.i. as the natural ZH protein. The gene discussed is IFNB1; the disease is infection.