CD44 and neoplasm: HA can be used as a tumor site-specific drug delivery method due to its high binding affinity for the CD44 receptor, a member of the cell adhesion protein family, which is overexpressed along the outermost layers of numerous carcinoma cells, including breast cancer cells.49 CD44, on the other hand, has been demonstrated to be expressed at very low levels on normal As a result, HA-modified nanoparticles or micelles appear to be viable carriers for CD44-targeted chemotherapy agents.50 HA has multiple functional groups that are employed in various conjugations and modifications.