['The present aimed to observe the effect of phosphatase inhibitor cyclosporine A on the subcellular location and on expression of HBcAg in HepG2.2.15 cells.', 'Thirty micrograms/ml of cyclosporine A (CSA) was added into HepG2.2.15 cell culture system and on days 2 and 4 HBcAg and HBsAg were respectively stained with fluorescent immunocytochemistry and observed under confocal microscope. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling method.', 'HBcAg was mostly expressed in cytoplasm in the control HepG2.2.15 cells. After 2 days CSA administration of the expression of HBcAg and HBsAg in cytoplasm significantly decreased and the signals of HBcAg in nucleus increased , whereas the HBcAg was still mainly expressed in nucleus in about 1/4 of the cells. Cell apoptosis was observed in about 30% of the cells.'] Does [ Cyclosporine A improve the nuclear entry of hepatitis B virus core protein in HepG2.2.15 cells ]?