Wang T. et al. designed a nano-drug delivery system in which HA-coated chitosan NPs promoted the drug delivery of 5—fluorouracil (5—Fu) into tumor cells that highly expressed CD44 and found that HA-chitosan NPs could effectively promote the enrichment of 5—Fu in A549 tumor cells with high expression of CD44 [146]. This evidence concerns the gene CD44 and neoplasm.