<p>A medicinal composition for treating and/or preventing neurodegenerative diseases which contains, as the active ingredient, a polypeptide represented by one of the following (a) to (c): (a) a polypeptide containing an amino acid sequence Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO:1); (b) a polypeptide containing an amino acid sequence derived from the amino acid sequence Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO:1) by deletion, substitution, insertion and/or addition of one to several amino acids and having an activity of inhibiting nerve cell death relating to neurodegenerative diseases; and (c) a polypeptide which is a modification of a polypeptide of (a) or (b); or a pharmaceutically acceptable salt thereof.</p>
