Expression of NRs in differentiating human CD34⁺ cells. (A-C) RNA-seq analyses were performed on primary human CD34⁺ cells induced to differentiate ex vivo under serum-free culture conditions.^21,31  The relative abundances (FKPM) of all 48 known NRs on differentiation days 4, 8, 11, and 14 are graphed in order of decreasing abundance. Note that the ordinate axis decreases by10-fold consecutively from the top panel down. (D-E) TR2/TR4, but not COUP-TFII, mRNAs and proteins were readily detected by qRT-PCR and western blotting assays in human CD34⁺ cells subjected to 2 different erythroid differentiation conditions.^16,31  Similarly, TR4, but not COUP-TFII, proteins were detected in MELs and flow-sorted Ter119⁺ (erythroid) cells from adult mouse spleen. Abundant COUP-TFII protein, on the other hand, were detected in Ter119⁻ (nonerythroid) adult mouse splenocytes. OAZ1 mRNA and anti-β-actin immunoreactivity were used as normalization controls in qRT-PCR and immunoblotting assays.