The invention concerns a purified polypeptide, comprising an amino acid sequence selected among: a) sequence SEQ ID n DEG 2; and b) a biologically active sequence derived from SEQ ID n DEG 2; and c) a fragment of the sequence SEQ ID n DEG 2 having a biological activity of the same type as that of the sequence SEQ ID n DEG 2 polypeptide, or immunologically related to the sequence SEQ ID n DEG 2 polypeptide.
