PCNA and neoplasm: Immunostaining analysis and terminal deoxinucleotidyl transferase-mediated dUTP-fluorescein nick end labelling (TUNEL) staining revealed that the rates of proliferating cell nuclear antigen (PCNA) and Ki67 positivity were lower, and the rate of apoptosis was higher in tumours derived from HepG2/miR-142-3p cells than in tumours derived from HepG2/control cells following sorafenib treatment (Fig. 7c).