Antibody which is directed against galectin-9 and is an inhibitor of the suppressor activity of regulatory T lymphocytes

A method of treating nasopharyngeal carcinoma in a human patient in need thereof comprising administering to the human patient an amount of an antibody directed against Galectin-9 effective to inhibit the suppressor activity of human regulatory T lymphocytes, thereby reducing tumor growth in the human patient, wherein the antibody has as CDRs

• the six CDRs defined by:
• the amino acid sequence SEQ ID NO:2 in the region H-CDR1;
• the amino acid sequence SEQ ID NO:3 in the region H-CDR2;
• the amino acid sequence SEQ ID NO:4 in the region H-CDR3;
• the amino acid sequence SEQ ID NO:6 in the region L-CDR1;
• the amino acid sequence SEQ ID NO:7 in the region L-CDR2;
• and
• the amino acid sequence SEQ ID NO:8 in the region L-CDR3.