The two ASTR populations identified by snRNAseq both expressed RFX4 and represent protoplasmic ASTRs, in MS lesions characterized by a downregulation of SLC1A2, and fibrous/reactive ASTRs that express more GFAP, CRYAB and MT3 in MS tissue [120]. The gene discussed is SLC1A2; the disease is myeloid sarcoma.