To further investigate inflammatory responses upon infection with Omicron subvariants in vivo, the mRNA of the lung hilum and periphery areas at 2 d.p.i. and modulation of four host genes (Cxcl10, Il-6, Isg15, and Mx-1) were evaluated (Fig. 5A and Supplementary Fig. 8). Here, ISG15 is linked to infection.