Human Herpesvirus 6 (HHV-6) is a member of the roseolovirus genus of the Betaherpesvirales subfamily isolated from patients with AIDS and other lymphoproliferateive disorders. It infects and replicates in fresh and established lines of hematopoietic cells and cells of neural origin. It also appears to alter the activity of NK cells. HHV-6 antibodies are elevated in patients with AIDS, Sjögren's syndrome, sarcoidosis, ME/CFS, and certain malignancies. HHV-6A is the most common cause of exanthema subitum and has been implicated in encephalitis. When HHV-6 integrates into the host genome it is referred to as ciHVH-6. When such virus integration occurs into the germline it is referred to as iciHHV-6. Description adapted from: https://www.ncbi.nlm.nih.gov/mesh/68015654.