CD44 and cancer: Hyaluronidase is involved in the progression of diseases such as cancer, rheumatoid arthritis and traumatic brain injury.[131] Pretreatment with hyaluronidase improves the transfection efficiency of pDNA in rat skeletal muscle.[132] The most common hyaluronic acid receptor, CD44, is copiously concentrated on the membranes of inflammatory cells and cancer cells, thereby contributing to active delivery.[133, 134] Hyaluronic acid is a commonly adopted for the construction of hyaluronidase‐responsive gene carriers.