(B) Left panel: wild-type (WT SMAD7 3'UTR) and mutated (MUT SMAD7 3'UTR; *: mutated nucleotides) miR-21-3p binding sequences in the humanSMAD7 3'UTR. Right panel: Luciferase reporter assay with wild-type (WT SMAD7 3'UTR) or mutated (MUT SMAD7 3'UTR) SMAD7 3'UTR in HEK293 cells overexpressing miR-21-3p (miR-21-3p mimic) or a scrambled sequence (Control). 