CAT and infection: In our system, RGNNV infection either apparently upregulated the Cu/Zn SOD or mild upregulates catalase, and Nrf2 as shown by western blot analysis (compare Fig. 2, lanes 2–4; 24 h, 48 h, and 72 h pi, respectively, with Fig. 2, lane 1 [0 h]) that catalase, and Nrf2 gene expression level have checked by RT-PCR and received a similar results to western blot analysis at 48 h and 72 h pi.