NRG1 and schwannoma: The mRNA expression level of the NRG1/ErbB system (Figure 2) and of glial markers (Figure 3) was examined by quantitative real-time PCR (qRT-PCR) in primary cultures of Schwann cells (SC) and olfactory bulb ensheathing cells (OEC) and was compared with the corresponding stable cell lines RT4-D6P2T (derived from a Schwannoma) and NOBEC (neonatal olfactory bulb ensheathing cells).