Proteic family of cytokins.

An isolated polypeptide having an identity of at least 80% with a polypeptide selected from the group consisting of: (a) a polypeptide comprising an amino acid sequence as shown in SEQ ID NO: 2 from amino acid residue 22 to the remainder amino acid 205; (b) a polypeptide comprising an amino acid sequence as shown in SEQ ID NO: 7 from amino acid residue 22 to amino acid residue 205; (c) a polypeptide comprising an amino acid sequence as shown in SEQ ID NO: 9 from amino acid residue 29 to amino acid residue 202; and (d) a polypeptide comprising an amino acid sequence as shown in SEQ ID NO: 11 from amino acid residue 29 to amino acid residue 202.