EPO and Alzheimer disease: Moreover, we observed a significant upregulation of PDGF-AA, EPO (Fig. 3G–I) and other neurotrophic factors such as Angiopoietin 2 and the granulocyte–macrophage colony stimulating factor (GM-CSF) (Fig. 3J, K) in 3D co-cultures from both HC and AD cohorts compared to their 3D mono-culture counterparts.