Patent ID: 7998469

Claim:
A modified interferon beta (IFN beta) cytokine, wherein said modified IFN beta cytokine differs from an unmodified IFN beta cytokine by two amino acid substitutions wherein said unmodified IFN beta cytokine comprises the amino acid sequence of SEQ ID NO: 196, or comprises a polypeptide with anti-proliferative activity having an amino acid sequence at least 95% identical to SEQ ID NO: 196 said two amino acid substitutions being either: (a) substitution of the 5th and 108th positions in SEQ ID NO: 196, or of the corresponding positions in the unmodified IFN beta cytokine comprising a polypeptide with anti-proliferative activity having an amino acid sequence at least 95% identical to SEQ ID NO: 196, with aspartic acid and serine, respectively; or (b) substitution of the 6th and 108th positions in SEQ ID NO: 196, or of the corresponding positions in the unmodified IFN beta cytokine comprising a polypeptide with anti-proliferative activity having an amino acid sequence at least 95% identical to SEQ ID NO: 196, with glutamine and serine, respectively, and wherein said two amino acid substitutions confer increased resistance to proteolysis over the unmodified IFN beta cytokine.