LAG3 is frequently co-expressed with PD-1 on tumor-infiltrating T cells across a variety of tumor types and has been shown to interact with major histocompatibility complex (MHC) class II, on antigen-presenting cells, to attenuate T cell activation.TSR-033 is an investigational, humanized, anti-LAG3 monoclonal antibody that blocks the interaction of the LAG3 receptor with MHC class II. The gene discussed is LAG3; the disease is neoplasm.