To explore its potential to inhibit EBV infection in ECs, we purified soluble 6×His-IFITM1 fusion protein (sIFITM1) (Extended Data Fig. 4a) and treated HEK293 cells with low (1 ng μl−1) or high (5 ng μl−1) concentration for 2 h before EBV-GFP exposure (Fig. 1g). Here, IFITM1 is linked to Epstein-Barr virus infection.