E2F7 and neoplasm: Instead, the gene levels (Fig. 4c) and protein expression (Fig. 4d) of E2F7 in re-differentiated cells were significantly reduced following FBS treatment and the gene level of E2F7 was negatively correlated with miRNA-302a or miRNA-302d in adherent HepG2 and Huh7 cells when compared with tumor spheres cultured in suspension (Additional file 1: Figure S3E, F).