Regarding the selection of HA as a polymer for the development of HA-DDSs for cancer therapy, it was reported that HA selectively binds to the cell surface adhesion receptor CD44 which is strongly expressed in many types of cancer and enhances the intracellular transport of anticancer drugs to numerous malignant cells, including breast cancer cells; hence, HA-containing systems can serve as advantageous carriers for successful chemotherapy [99]. This evidence concerns the gene CD44 and cancer.