HAVCR2 and neoplasm: Adding CD3xTRP1 treatment resulted in the emergence of a population of highly activated OT-1 T cells in the tumor, reflected by a significant upregulation of intracellular GzmB expression, and high expression of multiple activation markers, such as 4-1BB, CD27, NKG2A, PD-1 and Tim3 (Fig. 3b, c).