Third, independently of our NESP55 data, other changes in gene expression support a chromaffin phenotype of hypoxic neuroblastoma cells: up-regulation of IGF2 and of HIF2α, in particular, was strong evidence of this, as chromaffin-specific expression within the sympathetic nervous system of both of these genes was shown both in this and in previous investigations [9], [44], [45]. Here, IGF2 is linked to neuroblastoma.