On the other hand, the expression of the OX40 checkpoint molecule on AML blasts strongly associated with patients’ outcome and OX40high patients were found to have a significantly shorter survival compared to OX40low subjects, which held true both in terms of OS and PFS, thus representing the first description of the prognostic relevance of OX40 in AML. This evidence concerns the gene TNFRSF4 and acute myeloid leukemia.