ERVW-1 and myeloid sarcoma: On the other hand, PP-MS patients (Figures 3C, D) showed a positive significant correlation between anti-HHV-6A/B IgG antibodies titers and pHERV-W ENV/syncytin-1 protein expression levels in monocytes (r=0.479, p=0.038) and T lymphocytes (r=0.475, p=0.040).