LAG3 and neoplasm: Because LAG3 impacts functionality, it has been suggested that it can bind ligands other than MHC-II, the latter constitutively expressed on APC and B cells, inducibly expressed on CD4+ T cells and other immune (neutrophils and eosinophils) and stromal cells (fibroblasts) and also expressed on many types of tumor cells [49,50] (Figure 1 and Figure 2).