CD244 and chronic myelogenous leukemia, BCR-ABL1 positive: As T cell toxicity may be linked to cell exhaustion,29 we checked the expression of T cell immunosuppressive markers in CD8 T cells and found that the expression of four immunosuppressive markers TOX, LAG3, TIGIT, and CD244 were higher in CML patients (Fig. 1E), indicating that CD8 T cells may gradually lose their effector function due to long-term exposure to antigens and transform into exhausted T cells, thereby inhibiting the immune effect.30