HIF1A and neuroblastoma: Moreover, we included a set of invasiveness and pro-angiogenetic biomarkers (HIF-1α, VEGF, and PDGF), to verify whether ELF exposure might modulate neovascularization; malignant neuroblastoma is a highly vascularized solid tumor that requires access to blood vessels for growth, invasion, and metastasis [53, 54].