Therefore, the identification of the neurosecretory protein Spar downstream of Alk in the Drosophila CNS is particularly interesting in light of previous findings, where VGF (aka secretogranin VII) has been identified as one of the strongest transcriptional targets regulated by ALK in both cell lines and mouse neuroblastoma models (Borenäs et al., 2021; Cazes et al., 2014). This evidence concerns the gene SPAAR and neuroblastoma.