To analyze MeV restriction by BST2, a permissive (to both infection and transfection) cell line was generated as follows: The HEK293T cells were engineered to overexpress human SLAMF1 (293-hSLAM) using a standard lentivirus-based transduction system as described previously [21], with receptor expression being confirmed by flow cytometry. This evidence concerns the gene SLAMF1 and infection.