ERVW-1 and ovarian neoplasm: High levels of expression of HML-2 env, rec and np9 mRNA, and Env protein have been reported in ovarian cancer cell lines and tumors,16 whereas in another study Np9 mRNA was not detectible in two ovarian tumors tested.40 One possible mechanism of altered HML-2 expression in ovarian cancer may be due to alterations in its methylation status.15