However, LAG3 expression has also been reported in autoimmune-related CD4+ T cells and inflammation-inducing CD4+ T cell subsets, suggesting diverse functions depending on the context (36, 37) B7-H3, a member of the B7 family, is known as an immune checkpoint protein that is highly expressed on cancer cells, often correlating with poor prognosis (38–41). Here, LAG3 is linked to cancer.