Concordance of gene expression during terminal maturation of G1E-ER4 cells and primary fetal liver–derived erythroid cells (FLDECs). Signal log ratio (SLR) of transcript levels in differentiated versus undifferentiated G1E-ER4 cells (Y-axis, 0 versus 30 hours) and FLDECs³  induced to undergo erythroid maturation (X-axis, 0 versus 48 hours). Each symbol represents one gene that met nonbiased filtering criteria (SLR > 2, P < .005, threshold 100 in both systems). Top right and bottom left quadrants show transcripts with concordant expression trends in both experimental systems: bottom left quadrant (down-regulated in both): Brca2, Cdc20, Hsp60, Mybl2, Gstp2, Msh2, Akt (Pkb), Myb, Myc, Kit, Pcna, Mre11a, Nme2; top right quadrant (up-regulated in both): Ccng2, Pim1, Ube2b (Hr6b), Zfp36, Gadd45a, Prkcd, Bcl2l (Bcl-X_L), Ddit3 (Chop10), Mafk, U2af1-rs1, Cdkn1b, Mad, Csf2rb2. Transcripts not expressed concordantly in both systems: bottom right quadrant: Slc2a1, Pold1, Il4ra; top left quadrant: Myln, Ccnd3. An expanded description of these genes is available in supplemental data.⁴⁹