To further verify whether SVA infection induces the production of type III interferon in PK-15 cells, RT-qPCR was used to detect the mRNA level of IFN-λ1 and IFN-λ3 in PK-15 cells following SVA infection for 6, 12, 18, 24, and 36 h (MOI = 2). The gene discussed is IFNL1; the disease is infection.