Interfering with Rab27a inhibits secretion of exosomes and thus suppresses SVV transmission. Si-Rab27a interfering RNA (100 pmol) was transfected into IBRS-2 cells using liposome 2000. SVV was inoculated 24 h after transfection (si-Rab27a-SVV), the controls were transfected with Rab27a but not inoculated with SVV (si-Rab27a), and transfected with si-scr inoculated with SVV (si-scr-SVV), and transfected of si-scr but not inoculated with SVV(si-scr), and untreated cells-mock (non-treatment). A The expression of Rab27a mRNA in IBRS-2 cells was detected by RT-qPCR, and used GAPDH as a reference gene. B The expression of Alix mRNA in the cell was detected by RT-qPCR, and used GAPDH as a reference gene. C Exosomes were extracted from the culture supernatants of SVV-infected IBRS-2 cells, and the number of exosomes was detected by the NTA method. D The copy number of extracellular SVV in IBRS-2 cells was detected by RT-qPCR. Significance was calculated using a two-tailed t test and labeled as *P < 0.05 and **P < 0.01 in graphs. E IBRS-2 cells were infected with SVV for 1.5 h and then incubated with 1, 5, and 10 µmol of GW4869 for 36 h. An equal volume of DMSO was used as a control, and cells without any treatment were used as a negative control. The extracellular SVV copy number was detected using RT-qPCR.