There is provided the use of a polypeptide for the manufacture of a medicament for up-regulating IL-13RA2 gene expression in a mammal, wherein the polypeptide comprises a sequence of amino acid residues that is at least 90% identical to the sequence of amino acid residues of a polypeptide selected from: (a) a polypeptide comprising the amino acid sequence from residues 38 (Val) to 152 (Leu) as shown in SEQ ID NO:2; (b) a polypeptide comprising the amino acid sequence from residues 27 (Leu) to 164 (Thr) as shown in SEQ ID NO:2; (c) a polypeptide comprising the amino acid sequence from residues 24 (Ser) to 164 (Thr) as shown in SEQ ID NO:2; and (d) a polypeptide comprising the amino acid sequence from residues 1 (Met) to 164 (Thr) as shown in SEQ ID NO:2.