Neuronal differentiation in H9 cells. (a) Semiquantitative RT-PCR showing mRNA expression of neural crest specifiers p75, SOX-9, and SNAIL and the neuronal marker PRPH on days 0, 7, 14, and 21 of differentiation in the presence (+) or absence (−) of 10 ng/ml BMP4 on days 5–9 of differentiation with the SKNAS neuroblastoma cell line as a + control. (b) RT-PCR expression of p75, DBH, TH, and LIN28B expression in undifferentiated H9 cells and days 7, 14, and 21 of differentiation compared with control SHSY5Y and IMR-32 neuroblastoma cell lines, normal fetal adrenal gland (1 and 2) and fetal dorsal root ganglion. −ve = negative control.