The mouse erythroid lncRNA Redrum is not expressed in human erythroblasts. UCSC Genome browser³⁵  images of the mouse Redrum (Lnc046) locus (A) and the orthologous human region (B). Images for RNA-seq studies, histone modifications, and TF binding in erythroid cells are indicated. Note that active transcription (RNA-seq) and histone H3 chromatin marks occur in mice, but not humans. H3K4me3 marks the active promoter and H3K36me3 marks DNA polymerase II elongation. Mouse RNA-seq tracks are from primary fetal liver (Ter119⁺) erythroblasts, CD41⁺ megakaryocytes cultured from primary fetal liver erythroblasts, fluorescent-activated cell sorting–purified MEPs (all from this study), and mouse fetal liver erythroblasts analyzed by ENCODE. Mouse ChIP-seq tracks are from fetal liver (Ter119⁺) erythroblasts. Human RNA-seq tracks are from umbilical cord blood CD34⁺-derived erythroid cultures fractionated by flow cytometry into 5 different stages (pro, early basophilic, late basophilic, polychromatophilic, and orthochromatic erythroblasts).¹⁴  Histone modifications tracks are from ENCODE K562 erythroleukemia cells³⁶ ; the GATA1 track is from ENCODE peripheral blood–derived erythroblasts.³⁵