PDGFC and classic Hodgkin lymphoma: Our study shows that the two fundamental pathways PI3K and MAPK with PDGFC (platelet-derived growth factor C), in conjunction with the increased recruitment of its receptor PDGFR (platelet-derived growth factor receptor), which in turn also enhances MAPK signaling [55,56], were upregulated along with high mGluR5 expression in classical Hodgkin lymphoma cell lines.