This observation led us to test the functions of the SAGO-2/WAGO, which has previously been shown to be important for fighting viral infections.1,41 However, we found that knocking out sago-2 does not alter the expression of repetitive transgenes in both wild-type and pals-22(pig26) mutants (Figure 2A), suggesting that the antiviral RNAi pathway engages a different WAGO to distinguish exogenous/virus-derived RNA from repetitive transgenes. Here, CTSC is linked to viral infectious disease.