CD200 and neoplasm: Sacrifice of all mice 19d after surgical removal of the primary tumor showed that verteporfin blocked the effect of metformin in attenuating EMT6 metastasis to lungs in CD200-/- mice (Fig 6A), and decreased both the %CD8+ cells in DLN (Fig 6B) and CTL activity in splenocytes (Fig 6C) to baseline levels seen in CD200-/- mice receiving only surgery and immunotherapy.