CD80 and leukemia: Our previous study demonstrated that mature DCs with the uptake of tumor antigen-pulsed DC-derived EXO express pMHC I and costimulatory CD40, CD54, and CD80 molecules and can strongly stimulate antigen-specific CD8+ CTL responses and antitumor immunity, and our later studies also demonstrated that mature DCs with the uptake of TEXs and LEXs could induce tumor or leukemia antigen-specific CD8+ CTL responses and anti-leukemia immunity (29–32).