LAG3 and metastatic melanoma: On March 18, 2022, the combination therapy of relatlimab and nivolumab was approved by FDA for the treatment of unresectable or metastatic melanoma, making LAG3 the third FDA-approved immune checkpoint that was approved by FDA after CTLA-4 and PD-1 axis.423,424 This approval of LAG3 mAb marks an exciting beginning for this inhibitory receptor but many aspects of its biological functions still remain enigmatic.