Lymphocyte‐activation gene‐3, an important immune checkpoint in cancer

Immunotherapy has recently become widely used in lung cancer. Many oncologists are focused on cytotoxic T lymphocyte antigen‐4 (CTLA‐4), programmed cell death ligand‐1 (PD‐L1) and programmed cell death‐1 (PD‐1). Immunotherapy targeting the PD‐1/PD‐L1 checkpoints has shown promising efficacy in non‐small cell lung cancer (NSCLC), but questions remain to be answered. Among them is whether the simultaneous inhibition of other checkpoints could improve outcomes. Lymphocyte‐activation gene‐3 (LAG‐3) is another vital checkpoint that may have a synergistic interaction with PD‐1/PD‐L1. Here we review the LAG‐3 function in cancer, clinical trials with agents targeting LAG‐3 and the correlation of LAG‐3 with other checkpoints.