PD-1 and ICOS expression were analyzed in all patients before and after the standard induction therapy regimen.<h4>Results</h4>The expression of PD-1 and ICOS significantly decreased (66.7 and 16.3 fold, respectively) in AML patients following chemotherapy compared to its baseline value (P=0.01 and P=0.001, respectively). This evidence concerns the gene ICOS and acute myeloid leukemia.