Unless here we focused on an axis involving (non-coding and coding) RNA molecules, data obtained on the expression of VEGFA mRNA suggest that IGFBP2 may be upstream regulated by circSMARCA5 also at the protein level: indeed, IGFBP2 was described as an enhancer for the transcription of VEGFA in neuroblastoma cells [93] and IGFBP2 and VEGFA were shown to be positively correlated at the protein level in GBM tissues [94]. This evidence concerns the gene IGFBP2 and neuroblastoma.