Generation and identification of stably transfected HepG2 cells. (a) Measurement of VASH2 expression using qRT–PCR. VASH2 indicates VASH2-overexpressing HepG2 cells; EGFP indicates HepG2 cells transfected with a vector-expressing EGFP. Wt indicates wild-type HepG2 cells. The cells transduced with the three shRNAs and one control shRNA are designated as ‘sh1’, ‘sh2’, ‘sh3’ and ‘shcont’. VASH2-overexpressing HepG2 cells showed almost 1000-fold higher VASH2 expression than wild-type HepG2 cells, whereas VASH2-knockdown HepG2 cells had 80% lower expression when compared with wild-type HepG2 cells (*P<0.05 compared with the corresponding control group). (b) Western blots were used to confirm the efficiency of knockdown. The results are similar to those seen in the qRT–PCR analyses. (c) Gray scale analysis of the western blot data.