RIGI and viral infectious disease: Figure 1B shows that fish RNF135 has an enhancing effect on the activity of RIG-I CARDs, whereas TRIM25 has no effect. Nevertheless, TRIM25 co-expression with full-length RIG-I is required to protect EPC cells against a viral infection and to inhibit viral production (Figures 1D, E), highlighting that fish RNF135 and TRIM25 are both positive regulators of the RLR pathway.