ERVW-1 and granular cell tumor: However, the results from our study also indicate that presence of HML-2 Gag and Env antibodies in GCT patients is not correlated with expression of specific HML-2 proviruses, as several Gag- and Env-encoding HML-2 proviruses, among them c22_A, are transcriptionally active in both antibody positive and negative GCT patients.