CD81 and stroke disorder: For ease of description and study, the researchers further named the astrocytes located in the infarct area as "proximal astrocyte subgroups," and those located farther from the infarct core as "distal astrocyte subgroups." The proximal astrocyte subgroups showed significant upregulation of several genes related to fatty acid and cholesterol metabolism, such as Apoe, Clu, Cd81, Id3, and Fabp5, which may play a critical role in the metabolic coupling between astrocytes and neurons following stroke.