Knockdown irnar1 in T cells1. Evaluated the anti-tumor effects of knockdown of irnar1;2. Inhibited the growth;3. Increased the number of CD8+ TILs, characterized by the decreased expression of TIM3, CTLA-4, LAG3 and TOX and the enhanced expression of TCF1;. The gene discussed is CTLA4; the disease is neoplasm.