A nucleic acid construct which comprises a sequence of a 5 non-coding and promoter regions of Sortilin of an eukaryote organism, a selection gene cassette, said gene cassette having its own 5 and 3UTR flanking sequence on both side of its coding sequence, a sequence of a 3 coding region of Sortilin of said eukaryote organism, said sequence being driven by an anhydrotetracycline(ATc)-sensitive transactivator and its use in human and veterinarian medicine.