AFP and hepatocellular carcinoma: Recently, researchers observed that exosomes derived from a recombinant adeno-associated viral vector (rAAV)-carrying alpha-fetoprotein (AFP) gene (rAAV/AFP)-transfected DCs could effectively stimulate the proliferation of naive T cells and induce the activation of cytotoxic T lymphocytes (CTLs), thereby exhibiting immune responses against hepatocellular carcinoma (Li J. et al., 2018).