TGFB1 and neoplasm: Rats were killed at 0, 4, 8 and 12 weeks of experiment and blood and tissue samples were taken from all groups for the determination of tumour markers expression alpha-fetoprotein (AFP), transforming growth factor-β (TGF-β), M2-pyruvate kinase (M2-PK) and specific antigen for oval cells (OV-6).