Consequently, infection with the replication-competent molecular clone, NL-LucR.T2A-BaL.ecto, which was engineered to express the LucR reporter gene and the heterologous BaL env gene in cis with all of the HIV-1 open reading frames, permits highly sensitive and specific detection of active HIV-1 replication for several weeks after inoculation [12]. This evidence concerns the gene ERVW-1 and infection.