ERVW-1 and myeloid sarcoma: During the revision of the paper, a multicentric study has been published [89] on the association of MSRVenv antigenemia with MS, that independently confirmed our findings on increased positivity/expression levels of PBMC MSRV RNA and of MSRV DNA copy number in MS patients, and expression of MSRVenv protein within brain MS lesions; the HERV-W Env protein detection in MS sera confirmed our data on the association of circulating HERV-W/MSRVenv with MS.