Apoptosis assay: HEK-293 cells were transfected with the DNA plasmid pEGFP-C1 and pEGFP-C1-Lj-MAVS (5 μg or 10 μg) for 24 h using jetOPTIMUS® according to the manufacturer's instructions in 6-well chamber slides. All plasmids were extracted using the Pure LinkTM Hipure Plasmid Filter Midiprep kit. After 24 h, apoptosis-related proteins were detected via Western blot analysis. Luciferase activity assay: HEK-293 cells were seeded in 96-well plates and incubated for 16 h, after which the cells were transfected with plasmids (pEGFP-C1 and pEGFP-C1-Lj-MAVS or pcDNA3.1 and pcDNA3.1-Lj-RIG-I) using jetOPTIMUS®. After 24 h, each well was co-transfected with 0.2 ng luciferase reporter plasmid and 25 ng Renilla luciferase internal control vector. At 24 h post-transfection, IFN-β at 25 ng/mL was added to one well to stimulate the cells, which were then washed with PBS and lysed to measure luciferase activity using the Dual Luciferase Reporter Assay System. Antiviral activities of RRP4: The CO cells were transfected with 0.5 μg DNA plasmid pEGFP-N1-Lj-RRP4 or pEGFP-N1 with 1 μL jetOPTIMUS® according to the manufacturer's protocol. After 36 h, the cells were cultured in medium containing G418 to enrich the transfected cells. When a minimum of 90% of cells were RRP4- and EGFP-positive, they were collected, and total protein was extracted for WB to detect the effect of stabilization. Subsequently, for antiviral assays, the stably transfected RRP4 and EGFP cells were seeded into a 96-well plate at approximately 80% confluence, 12 h before GCRV infection.