As our initial qRT-PCR analysis revealed decreased PDGFRα and PDGFB in gastroparesis subjects (Fig. 1b) we further validated a number of the mRNAs predicted to be regulated by PDGF BB (Additional file 7: Table S4) This analysis confirmed the downregulation of almost all the predicted PDGF BB targets that we examined and revealed that these changes were specific to the idiopathic gastroparesis subjects as none of these target genes were significantly affected by obesity (Fig. 5). The gene discussed is PDGFB; the disease is obesity due to melanocortin 4 receptor deficiency.