HMOX1 and myeloid sarcoma: In the normal Central Nervous System (CNS), HO-1 mRNA and protein are normally confined in scattered neurons and neuroglia, but the HO-1 gene is upregulated in glial cells within MS plaques in the vicinity of human cerebral infarcts, haemorrhages, and contusions, as well as in various other degenerative and non-degenerative human CNS disorders.