Another study showed that the expression of HVEM was considerably elevated in αβ+ T cells in the low-risk group of acute myeloid leukemia (AML) patients, but CTLA-4 on γδ+ T cells and PD-1 ligand on blasts were both correlated with poor relapse-free survival in ALL patients [56]. This evidence concerns the gene CTLA4 and acute lymphoblastic leukemia.