A recent study has demonstrated that FGL1 is a major immune inhibitory ligand for LAG3, and the interaction between FGL1 and LAG3 can inhibit the anti-tumor effect of T cells in vitro and in vivo, while FGL1 gene silencing can promote the anti-tumor effect of T cells in the mouse model (18), thus reveals a new immune escape mechanism. The gene discussed is LAG3; the disease is neoplasm.