LAG3 and neoplasm: Although MHC-II was reported to be the canonical ligand for LAG3, studies using a rat mAb (clone C9B7W) to mouse LAG3 that binds to the D2 domain without disrupting LAG3/MHC-II interactions reported that C9B7W improved anti-tumor responses associated with enhanced T cell proliferation and effector function (relative to responses elicited by an isotype-matched control antibody) (39, 40).