They found that clathrin heavy chain (Cltc) plays a significant role in mediating endocytosis of the exosomes in the liver and spleen, and blocking it caused therapeutic exosomes (based miR-21a delivery) to be more efficiently distributed to targeted organs, such as the heart, and produced a much better therapeutic effect on cardiac function in the DOX-induced cardiotoxicity mouse model [171]. The gene discussed is CLTC; the disease is cardiotoxicity.