DLK1 and neoplasm: Interestingly, in neurobastoma, another tumor in which DLK1 is highly expressed under hypoxic conditions and where it plays a role in the maintenance of a stem-like phenotype of the cancer cells, DLK1 ICD plays a fundamental role.10 In this tumor setting, in fact, two highly conserved phosphorylation sites localized in the ICD are necessary for the pro-stemness activities of hypoxia-induced DLK1, as ablation of the phosphorylation sites or deletion of the whole DLK1 ICD results in a significant reduction in the cancer cells’ clonogenic abilities.10