CD46 and myeloid sarcoma: Lastly, increased levels of a soluble CD46 receptor, a complement system regulator, and the human receptor for HHV-6, have been found in the CSF and blood of MS patients [193], leading to the hypothesis that HHV-6 infection, through the engagement of CD46, might induce exaggerated activation of the complement system which could contribute to MS pathogenesis [194].