A doxorubicin hydrochloride (Dox) loaded CD44-targeted drug delivery system based on hyaluronic acid modified mesoporous silica nanoparticles (MSNs) has been developed and shown greater cytotoxicity to HCT-116 (human colon cancer cells) than free Dox and nontargeted MSNs [106]. The gene discussed is CD44; the disease is colonic neoplasm.