We further confirmed the essential role of CXCL8 expression in EV-D68 infection in diverse immortalized cell lines, including A549, BEAS-2B, and CALU-3 respiratory cells and other EV-D68-permissive cell lines, namely, HEK293T cells and RD cells (Supplementary Figs. 1 and 2). Here, CXCL8 is linked to infection.