CDK9 and infection: To exclude the possible off-target effect of LDC and confirm that diminished CDK9 expression could decrease IFV replication, CDK9 siRNAs were used to silence CDK9 expression (Fig. 5C), which clearly led to a decrease in IFV replication, as evidenced by a notable decrease in virus titers against five different IFV strain infections (Fig. 5D through H).