DLK1 and Alzheimer disease: These included GLUL, a glutamine synthetase hypothesized to provide neuroprotection in AD patients, (Kohane and Wood, 2021 preprint) and DLK1, a Notch ligand involved in sub-ventricular zone neurogenesis (Ferrón et al., 2011), both of which are upregulated in human hpIPCs compared with chimpanzee hpIPCs.