In order to further explore the differences of ErbB4 expression between our study groups, we studied the mRNA level of expression of ErbB4 by real-time PCR and found significant lower relatives expression of ErbB4 mRNA in RR-MS patients (1067.0 ± 239.0) as compared to HC (1903.1 ± 265.3, P = 0.030) (Figure 2). This evidence concerns the gene ERBB4 and myeloid sarcoma.