PSEN1 and Alzheimer disease: On the other hand, the replacement of AD with healthy glia was not sufficient to protect from neurodegeneration, suggesting the pivotal role of mutated PSEN1 in neurons.<h4>Conclusions</h4>We herein succeeded in reproducing crucial AD-related changes in iPSC-derived <i>in vitro</i> models providing new insights in the neuropathological communication amongst brain cells, thus representing a promising tool to deepen disease mechanisms and develop neuroprotective treatments.