The expression of LAG-3 is regulated by glycogen synthase kinase-3 (GSK-3), and attempts at decreasing LAG-3 transcription in T cells and NK cells using a GSK-3β inhibitor have shown that this is a viable strategy to counteract B16 melanoma growth in the lung.29 In another approach, instead of blocking LAG-3 signalling, LAG-3 fused to the Fc region of IgG1 (LAG-3Ig or IMP321) can be used as an MHC-II agonist to activate dendritic cells and anti-tumour T-cell responses through so-called immunopotentiation. Here, LAG3 is linked to melanoma.