A MONOCLONAL ANTI-CD44 ANTIBODY, OR ANTIGEN-BINDING FRAGMENT THEREOF, FOR USE IN THE TREATMENT OF A HEAD AND NECK SQUAMOUS CELL CARCINOMA (HNSCC) IN A MAMMAL, WHEREIN SAID HNSCC IS CHARACTERIZED BY THE EXPRESSION OF CD44. SAID MONOCLONAL ANTIBODY MAY BE PRODUCED BY THE HYBRIDOMA DEPOSITED WITH THE ATCC WITH THE ACCESSION NUMBER PTA-4621, AND MAY BE CHIMERIC OR HUMANIZED VERSIONS THEREOF. (NO SUITABLE FIGURE)