a, TaqMan PCR measurements of mature miR-21 expression levels in wildtype cells and CRISPR/Cas9 MIR21 deletion-clones. Values are normalized to spike-in control. b, Intracellular ZIKV RNA in MIR21 knockout and wildtype cells. Two-sided Student’s t-test p-values: ** =0.001; *** =0.0002, 4 degrees of freedom. c, Expression level of control and miR-21 psiCHECK-2 reporters upon treatment with miR-21 or control inhibitors. miR-21 expression values denote for Renilla/Firefly luminescence signals. d, Intracellular ZIKV RNA in miR-21 inhibited and control cells. Two-sided Student’s t-test p-value: *** =0.0003, 4 degrees of freedom. e, Replication of a ZIKV replicon carrying a wildtype 5′ CS or a 5′; CS - 3′ CS double mutant, pre-treated with miR-21 or non-targeting inhibitors. Two-sided Student’s t-test p-values: **** =3.5E-07; n.s.= 0.1 (non-significant), 10 degrees of freedom. wt: wildtype; KO: CRISPR-Cas9 MIR21 deletion-clones; cont: control. Mean and s.d. of 3 (a, b, d), 4 (c), and 6 (e) biologically independent samples are shown.