Fig. 3

The SMAD4 gene is a downstream target of miR‐6881‐3p but not TGFBR1. A, B The miR-6881-3p binding site and mutation sites in the 3’-UTR of SMAD4 or TGFBR1; C The luciferase reporter assay showed direct binding between miR-6881-3p and the SMAD4 3’-UTR; D The luciferase reporter assay showed indirect binding between miR-6881-3p and the SMAD4 3’-UTR; E qRT‐PCR analysis of SMAD4 mRNA expression after transfection in KGN cell; F qRT‐PCR analysis of TGFBR1 mRNA expression after transfection in KGN cell; G, H Western blot analysis of SMAD4 protein levels after transfection in KGN cell (The original image is shown in Figs. S2 and S3); I, J The expression of SMAD4 in KGN cells detected by immunofluorescence staining. **P < 0.01