Abstract: The present invention relates to the human and murine melanoma inhibitory activity protein-2 (MIA-2) and to the nucleic acids encoding said proteins including a method for producing such proteins by recombinant techniques. The invention also relates to methods for utilizing such proteins for tissue regeneration, tumor treatment including to control the proliferation and differentiation of liver cells in vivo and in vitro. The invention further relates to diagnostic assays including the human and murine antibodies or aptamers and their use in therapy and diagnosis. Further it relates to diagnostic assays applying specific primers for the diagnostic of liver disease.