Neurotoxic A1‐like astrocytes are abundant in many human neurodegenerative diseases, and induced by activated microglia with high level of A1 specific markers (including Fbln5 [fibulin 5], RT1‐S3 [RT1 class 1b, locus S3], Serping1 [serpin family G member 1]) and low level of A2 specific markers (including Clcf1 [cardiotrophin‐like cytokine factor 1], Tgm1 [transglutaminase 1] and Ptgs2 [prostaglandin‐endoperoxide synthase 2]) 12. The gene discussed is TGM1; the disease is neurodegenerative disease.