CD44 and cancer: CD44 has proposed roles in leukocyte-endothelial interactions, there is increasing evidence of several potential mechanisms by which CD44 may play an aetiological role in certain cancers and vascular diseases [35,53,55,59,60], there are reputed diagnostic associations between CD44 profiles and various diseases, and there are undoubted connections between tobacco use and specific cancers and certain life-threatening inflammatory processes.