The rNA-wt caused the most rapid death in mice which started on 5 days p.i. and all of the mice in the virus group were dead by 8 days p.i. However, mice infected with rWSN-like, rH5N1/97-like, rH7N1/99-like, rH5N1/96-like, rSA10 or rSD10 displayed 1- to 3-day delay in death compared with mice infected with rNA-wt, and all mice except rPR/8-like and rSD20 groups succumbed to infection by day 11 p.i. (Fig. 4b). Here, EXTL3 is linked to infection.