CEACAM1 and neuroblastoma: Our present studies reveal that VEGF is positively correlated with neuronal differentiation of NB both in vivo and in vitro, which is compatible with a previous study showing upregulation of VEGF and CEACAM1, a pro-angiogenic factor and mediator of VEGF-driven angiogenesis, during differentiation and maturation of neuroblastic tumors19.