In a Phase 1 study (MK-4280-001; NCT02720068) evaluating anti-LAG-3 IgG4 monoclonal antibody favezelimab in MSS CRC, no patients achieved clinical response with monotherapy treatment, and 6.3% achieved an objective response when administered in combination with an anti-PD-1 [23]. Here, LAG3 is linked to colorectal carcinoma.