PDCD1 and acute myeloid leukemia: Accordingly, we showed that a LysM- Cre Flt3-ITD/Tet2 AML mouse model, similar to the previously described Vav-Cre Flt3-ITD/Tet2 model [34] but retaining wild-type T cells, phenocopies the immune exhaustion and PD1 refractoriness found in many patients with AML.