As a result of this cleavage, the extracellular region transforms into sLAG-3.[12,13] On one hand, it has been demonstrated that the presence of sLAG-3 can augment the proliferation and immune functionality of CD8+ T and Th1 cells.[14] On the other hand, the level of sLAG-3 in peripheral blood can serve as a prognostic biomarker for patients undergoing treatment, although its significance varies depending on the type of cancer.[15–18] The elucidation of the physical and pathological significance of sLAG-3 requires further investigation. Here, LAG3 is linked to cancer.