2 Cells involved in the anti-colon cancer (1)Nk cell Kills many types of tumor cells, especially cells reduced class I MHC expression and can escape killing by CTL (2)ap T cells lp T cells contains the mhc i restricted CD8+ Ctl and MHC li restricted with CD4+ th cell. The activated CD4+ cells promote the activation of the CTL, and activate the Mg in tumor immunity. After the activation of CTL, kill the tumor cells directly and kill the cytokines(IFN-Y)indirectly (3)Yo T cells Not restricted by Mhc and kill cells that could escape from NK cells2. Cells involved in the anti-colon cancer (1) NK cell: Kills many types of tumor cells, especially cells reduced classⅠ MHC expression and can escape killing by CTL. (2) αβ T cells: αβ T cells contains the MHCⅠ restricted CD8+ CTL and MHCⅡ restricted with CD4+ Th cell. The activated CD4+ cells promote the activation of the CTL, and activate the MΦ in tumor immunity. After the activation of CTL, kill the tumor cells directly and kill the cytokines (IFN-γ) indirectly. (3) γδ T cells: Not restricted by MHC and kill cells that could escape from NK cells