In a first step, we verified that free virus infection with Env-pseudotyped NLinGluc reporter viruses, like the commonly used reporter virus NLlucAM [65] which encodes for firefly luciferase, requires DEAE for efficient infection of A3.01-CCR5 T cells (Fig 1A, S1 Fig). This evidence concerns the gene ERVW-1 and viral infectious disease.