IFN signaling is increased in LKS and myeloid progenitor compartments of FLT3-ITD mice in the absence of miR-155. (A) Heat map showing gene expression differences in protein-coding genes identified by RNA sequencing of the LKS compartment of WT, FLT3-ITD, and FLT3-ITD 155^−/− mice. (B) GSEA of LKS compartment RNA sequencing data identifies the IFN-α response and IFN-γ response as hallmark differences between FLT3-ITD and FLT3-ITD 155^−/− mice. (C) Volcano plot showing LKS compartment gene expression changes in FLT3-ITD 155^−/− vs FLT3-ITD mice. Dashed line represents a P value = .05. Yellow dots indicate IFN-α/γ–responsive genes as annotated by GSEA. (D-E) qRT-PCR analysis of representative IFN-responsive genes in the LKS or myeloid progenitor compartment of FLT3-ITD or FLT3-ITD 155^−/− mice (n = 5 for each group). Expression normalized to L32, with the FLT3-ITD average set to a relative expression value of 1. (F) Western blot of STAT1 in LK-sorted BM of FLT3-ITD or FLT3-ITD 155^−/− mice; replicates represent individual mice. ACTIN serves as the loading control. *P ≤ .05 FDR, false discovery rate; NES, normalized enrichment score.