VSIG4 and viral infectious disease: Although Vsig4 deficiency did not seem to affect the basal expression level of these factors before viral infection (Supplementary Fig. 3), qRT-PCR data showed that MHV-3 infection super-induced Vsig4−/− PEMs to express Fgl2, Tnf, Il-1β, and Il-6 (Fig. 2e).