CD44 and cancer: After DDM treatment, the expression levels of HA, CD44, and FR-α were markedly reduced in MCF-7 cells + DDM by 64.6%, 54.6%, and 55.9%, respectively, and in MDA-MB-231 cells + DDM by 43.7%, 53.8%, and 60.4%, respectively, when compared with DDM-free cancer cells.