miR-302a-3p downregulation results in enhanced IRF9 expression upon ADAR1 knockdown. (A) Right panels: Immunoblot results showing increased STAT1, p-STAT1, and IRF9 in ADAR1 KD cells. Left panels: Immunoblot results showing unchanged protein levels of IRF3, JAK1, and MDA5, the upstream targets of STAT1 and IRF9. (B) Alignment between IRF9 UTR and miR-302a-3p showing seed sequence matching with the 3′-UTR of IRF9 mRNA. (C) Real-time PCR results of miR-302a-3p in control and ADAR1 KD cells. (D) Luciferase reporter assay result of wild-type IRF9 UTR reporter (WT) or UTR mutant with the seed-binding site of miR-302a-3p (MUT), co-transfected with the miR-302a-3p mimic or scrambled control. (E) Immunoblot images showing STAT1 and IRF9 level in control and ADAR1 KD cell lines, treated with the miR-302a-3p mimic or scrambled control. * p < 0.05, *** p < 0.001.