Heatmap showing a subset of genes differentially expressed between day-29 GFP⁻and GFP⁺sorted fractions. Heatmap illustrating downregulation of ribosomal transcripts, upregulation of a subset of genes involved in the ubiquitin-proteasome system (UPS) pathway and increased expression of genes linked to erythroid maturation in GFP⁺ vs GFP⁻ cells. In addition to genes coding for ribosomal proteins, this heatmap contains a selection of genes identified in supplemental Figure 4 as linked to erythroid maturation based on comparison of transcriptomic data sets representing terminal erythroid maturation found in the literature.^40,44  The UPS-related genes shown represent a subset of these erythroid maturation genes identified in supplemental Figure 4.