P21 expression and its relation to disease activity and hepatocyte proliferation in chronic hepatitis B virus infection - VARLI, Murat; OKÇU HEPER, Aylin; ERDEN, Esra; UZUNALİMOĞLU, Özden; YURDAYDIN, Cihan; BOZKAYA, Hakan (Turkish Journal of Gastroenterology, 2005)