Prl2 deficiency alters gene transcription in murine HSPCs. (A) Heat map of Prl2-regulated genes that are upregulated (red) or downregulated (blue) (log₂FC < −1, FDR < 0.05, P < .05) in Prl2 null E14.5 (embryonic day 14.5) fetal liver cells compared with WT fetal liver cells. (B) GSEA analysis of gene transcription between WT and Prl2 null E14.5 fetal liver cells. HSC, receptor tyrosine kinases, PI3KAKT signaling pathway, and MAPK pathway gene signatures were significantly downregulated in Prl2 null E14.5 fetal liver cells. (C) GSEA showed that receptor regulator activity, receptor complex, cell surface, and receptor protein tyrosine kinase gene signatures were significantly downregulated in Prl2 null E14.5 fetal liver cells. (D) GSEA showed that regulation of receptor signaling pathway, positive regulation of ERK1 and ERK2 cascade, and positive regulation of MAPK cascade gene signatures were significantly downregulated in Prl2 null E14.5 fetal liver cells. (E) STRING protein-protein interaction network between downregulated genes (log₂FC > 1, FDR < 0.5, P < .05) related to FLT3 signaling in Prl2 null E14.5 fetal liver cells. (F) Quantitative RT-PCR analysis of gene expression in WT and Prl2 null E14.5 fetal liver cells (n = 4). (G) Quantitative RT-PCR analysis of gene expression in WT and Prl2 null BM Lin⁻ cells (n = 4). (H) Immunoblot analysis of AKT, STAT5, and ERK phosphorylation in WT and Prl2 null E14.5 fetal liver cells (n = 3). (I) Immunoblot analysis of AKT, STAT5, and ERK phosphorylation in WT and Prl2 null BM Lin⁻ cells (n = 3). Mean values (±SEM) are shown (∗P < .05, ∗∗P < .01, and ∗∗∗P < .001). BM, bone marrow; FDR, false discovery rate; RT-PCR, reverse transcription polymerase chain reaction.