NP23 B-lineage leukemia gene signature is enriched in fetal liver fraction BC and pro–B-1 cells. (A) Heat map shows clustering of 106 NP23 leukemia core genes (>2-fold upregulated in NP23 B-lineage leukemias) in expression array data from isolated B-cell populations (GSE15907). Fetal liver (FL) fraction (Fr) BC profile is boxed in red; bone marrow (BM) fraction BC profile is boxed in blue. (B) GSEA plot showing enrichment of NP23 leukemia core upregulated genes in FL Fr BC compared with BM Fr BC (GSE15907). (C) Enrichment of NP23 leukemia core upregulated genes in pro–B-1 vs pro–B-2 cells²³  (GSE81411). FDR, false-discovery rate; LN, lymph node; MLN, mesenteric LN; NES, normalized enrichment score; PC, peritoneal cavity; SP, spleen.