ALDH1L1 and Alzheimer disease: Following this method, we were able to generate a pure population of astrocytes from hiPSC lines from APOE4/4 AD patients (AD astrocytes from now on) and from age-matched APOE3/3 cognitively healthy subjects (CTRL astrocytes from now on), which expressed canonical astrocytic markers as ALDH1L1 (aldehyde dehydrogenase 1 family member L1) (Fig. 1B b1-3) and GLAST (Fig. 1B b4-6).