The expression levels of the 10 genes selected (Hrad 6B, annexin A2, BMP-7, contactin-1, peroxiredoxin-1, heat shock transcription factor-2, synaptotagmin IV, serotonin receptor-7, Axl, and IL-15) were analyzed by RT-PCR, by using total RNAs obtained from 5 samples (Fig. 4B) . The expression levels of 9 genes (Hrad 6B, annexin A2, BMP-7, contactin-1, peroxiredoxin-1, heat shock transcription factor-2, synaptotagmin IV, serotonin receptor-7, Axl) were low in undifferentiated cells and increased in differentiated cells by RT-PCR and microarray, but the expression pattern of IL-15 was different. Expression level of IL-15 tended to be decreased in microarray, but increased in RT-PCR (Fig. 5 ).