Wang et al. (2012) showed that the delivery of suicide gene and doxorubicin through CD44-conjugated liposomal nanoparticles that specifically target CD44+ tumorigenic cells of hepatocellular carcinoma (HCC) resulted in the induction of apoptosis and inhibition of tumor growth. Furthermore, Rao et al. (2015) developed a doxorubicin-encapsulated polymeric nanoparticle covered with chitosan to target and kill CD44+ mammary cancer stem-like cells. Here, CD44 is linked to breast cancer.