In the immunotherapy of malignant tumors, new potential targets include Lymphocyte-activation-gene-3(LAG-3), T cell immunoglobulin and mucin-containing molecule 3 (TIM-3), and T cell immune receptor with Ig and ITIM domains(TIGIT), their clinical significance in DLBCL is unclear.LAG-3 is a type I transmembrane protein encoded by the LAG-3 gene. The gene discussed is LAG3; the disease is cancer.