Abstract: The application relates to gene constructs for inducible hepato-specific expression of polynucleotides of interest in response to an inducer agent, said constructs comprising (i) an inducible bi-directional operator-promoter with at least one responsive element to said inducer agent flanked by two hepato-specific promoters acting in divergent manner, (ii) a first nucleotide sequence encoding a transactivator which may be activated by said inducer agent operatively coupled to the first hepato-specific promoter and (iii) a second nucleotide sequence operatively coupled to the second hepato-specific promoter, wherein the promoters are induced as a consequence of the binding of the transactivator to the operator region of the operator-promoter in the presence of the inducer agent.