LAG3 and cancer: In addition to PD‐L1, ligands expressed at the surface of cancer cells and immunosuppressive cells include PD‐L2, galectin‐9, CEACAM1, CD70, CD137L, OX40L, ICOSL, and corresponding receptors: T‐cell immunoglobulin mucin receptor 3 (TIM3; HAVCR2), lymphocyte activation gene 3 (LAG3) regarding the coinhibitory receptors, and costimulatory receptors CD27, CD137, OX40, GITRL, or ICOS (Mahoney et al., 2015; Melero et al., 2015).