Early fetal liver erythropoiesis associated with c-myb, Sox6, and Bcl11A erythroid transcription factors. Expression of common erythroid transcription factors (GATA-1, EKLF) and those uniquely expressed in definitive erythroid lineages (c-myb, Sox6, and Bcl11A) in primitive erythroid cells from peripheral blood (PB) and in definitive proerythroblasts sorted from fetal liver (FL) and BM was determined by qPCR. Error bars indicate SEM and n = 3.