IFNG and Alzheimer disease: Secondly, comparison of HC and AD MDMi secretory profiles in 3D co-culture showed that AD cells secreted higher levels of platelet-derived growth factor AA (PDGF-AA) and erythropoietin (EPO), and lower levels of interferon-γ (IFN-γ), compared to HC (Fig. 3G–I; Additional file 5: Dataset S4).