背景资料:The immune checkpoint protein TIM3 is a member of the immunoglobulin superfamily and TIM family of proteins that was initially identified as a specific marker of fully differentiated IFN-γ producing CD4 T helper 1 (Th1) and CD8 cytotoxic cells. It is a Th1-specific cell surface protein that regulates macrophage activation and negatively regulates Th1-mediated auto- and alloimmune responses, and is also highly expressed on regulatory T cells, monocytes, macrophages, and dendritic cells (1). TIM3 and PD-1 are co-expressed on most CD4 and CD8 T cells infiltrating solid tumors or in hematologic malignancy in mice; blocking TIM3 in conjugation with a PD-1 blockade increases the functionality of exhausted T cells and synergizes with to inhibit tumor growth (2,3).