ERVW-1 and infection: To further strength this result, most non-specific inhibitions have been excluded in our study by the fact that C17-Chol only specifically inhibited the infection of pseudoviruses carrying HIV-1 Env but not VSVG, and conjugating cholesterol to the N-terminal of C17 peptide could not inhibit HIV-1 infection due to the inappropriate orientation of the peptide on cell membrane.