NTN4 and neoplasm: Although human diseases directly associated with loss-of-function mutations have not been identified, a SNP in the netrin-4 gene (causing Y205H) has been associated with late onset Alzheimer’s disease (Saad et al., 2015), and dysregulation of expression appear to contribute to tumor pathogenesis and point toward an additional important aspect of BM biology (Schneiders et al., 2007; Reuten et al., 2016, 2021; Troughton et al., 2020c).