It has been reported that CD8+ T cell‐derived exosomes could activate the innate immune response which is beneficial for tumor immunotherapy.[79] In a recent study, the surface‐engineered exosomes with CD62L (a gene for lymphocyte homing to lymph nodes) and OX40L (a gene for regulation of T cells) could activate effector T cells, consequently amplifying the antitumor immune response and inhibiting tumor development.[80] In addition, interest in exosome‐based anticancer vaccines has increased. Here, CD8A is linked to neoplasm.