An analog of interferon gamma (IFNγ), wherein the moiety mediating binding to its natural receptor is at least functionally disrupted and wherein the analog comprises a signaling moiety capable of mediating intracellular IFNγ activity, wherein the signaling moiety comprises at the C-terminal end of the analog a sequence selected from the group consisting of (a) the amino acid sequence KFEVNNPQVQRQAFNELIRVVHQLLPESSLRKRKRSR; (b) the amino acid sequence YSVTDLNVQRKAIHELIQVMAELSPAAKTGKRKRSQ; (c) an amino acid sequence showing at least 90% identity to (a) or (b) provided that the intracellular signaling activity is maintained; (d) the amino acid sequence under (a) or (b) wherein at most 5 amino acid residues are deleted, added or substituted, provided that the signaling activity, for example nuclear translocation, is maintained; (e) the consensus sequence Vxxxx[V/I]Q[R/H][Q/K]A[F/V/I][N/H]ELI[R/Q] Vx[H/A][Q/E]L[L/S]P[E/A][S/A][S/A][L/K]xxKRKRS wherein x is any amino acid residue; and (f) the sequence Xaa 1 Xaa 2 Xaa 3 Xaa 4 Val Xaa 5 Xaa 6 Xaa 7 Xaa 8 Xaa 9 Gln Xaa 10 Xaa 11 Ala Xaa 12 Xaa 13 Glu Leu Ile Xaa 14 Val Xaa 15 Xaa 16 Xaa 17 Leu Xaa 18 Pro Xaa 19 Xaa 20 Xaa 21 Xaa 22 Xaa 23 Lys Arg Lys Arg Ser Xaa 24 Xaa 25, wherein Xaa 1, Xaa 2, Xaa 3 Xaa 4 Xaa 6 Xaa 11, Xaa 13, Xaa 14, Xaa 16 Xaa 17, Xaa 18 Xaa 19 Xaa 20 Xaa 21 Xaa 22 Xaa 23 Xaa 24 and Xaa 25 is any amino acid residue Xaa 5 is Asn or Thr Xaa 7 is Pro or Leu Xaa 8 is Gln or Asn Xaa 9 Val, Ile or Leu Xaa 10 is Arg, His or Lys Xaa 12 is Phe, Val or Ile Xaa 15 is Val, Ile or Met said signaling moiety being provided at its N-terminus, optionally via a linker, with at least one targeting domain capable of binding to a cell surface receptor other than the IFNγ receptor, wherein said targeting domain can bind to the PDGFβ receptor, the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/ IGF2R), the asialoglycoprotein (ASGP) receptor or the mannose receptor (CD 206). (a) the amino acid sequence KFEVNNPQVQRQAFNELIRVVHQLLPESSLRKRKRSR; (b) the amino acid sequence YSVTDLNVQRKAIHELIQVMAELSPAAKTGKRKRSQ; (c) an amino acid sequence showing at least 90% identity to (a) or (b) provided that the intracellular signaling activity is maintained; (d) the amino acid sequence under (a) or (b) wherein at most 5 amino acid residues are deleted, added or substituted, provided that the signaling activity, for example nuclear translocation, is maintained; (e) the consensus sequence Vxxxx[V/I]Q[R/H][Q/K]A[F/V/I][N/H]ELI[R/Q] Vx[H/A][Q/E]L[L/S]P[E/A][S/A][S/A][L/K]xxKRKRS wherein x is any amino acid residue; and (f) the sequence Xaa 1 Xaa 2 Xaa 3 Xaa 4 Val Xaa 5 Xaa 6 Xaa 7 Xaa 8 Xaa 9 Gln Xaa 10 Xaa 11 Ala Xaa 12 Xaa 13 Glu Leu Ile Xaa 14 Val Xaa 15 Xaa 16 Xaa 17 Leu Xaa 18 Pro Xaa 19 Xaa 20 Xaa 21 Xaa 22 Xaa 23 Lys Arg Lys Arg Ser Xaa 24 Xaa 25, wherein Xaa 1, Xaa 2, Xaa 3 Xaa 4 Xaa 6 Xaa 11, Xaa 13, Xaa 14, Xaa 16 Xaa 17, Xaa 18 Xaa 19 Xaa 20 Xaa 21 Xaa 22 Xaa 23 Xaa 24 and Xaa 25 is any amino acid residue Xaa 5 is Asn or Thr Xaa 7 is Pro or Leu Xaa 8 is Gln or Asn Xaa 9 Val, Ile or Leu Xaa 10 is Arg, His or Lys Xaa 12 is Phe, Val or Ile Xaa 15 is Val, Ile or Met said signaling moiety being provided at its N-terminus, optionally via a linker, with at least one targeting domain capable of binding to a cell surface receptor other than the IFNγ receptor, wherein said targeting domain can bind to the PDGFβ receptor, the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/ IGF2R), the asialoglycoprotein (ASGP) receptor or the mannose receptor (CD 206).