MAP2K3 and hepatocellular carcinoma: In the this study, an adenoviral vector of miR-21 sponge that containing a tandem of eight binding sites of miR-21 was generated and tested in HCC HepG2 cells, the HepG2 cells transduced with the sponges showed a significant inhibition of miR-21 expression, and as a consequence, the expression of new identified miR-21 targeted gene, MAP2K3 was augmented.