HTR1B and myelodysplastic syndrome: As shown in Fig. 2A–D, the expression of HTR1A, HTR1B, DRD3 and DRD5 was significantly higher in all MDS subgroups as compared to HD samples, with the exception of MDS-RS (MDS with ring sideroblasts) with multilineage dysplasia (MDS-RS-MLD), which showed only an increase in DRD3 expression.