SELL and Epstein-Barr virus infection: However, there was a greater decrease in CCR7 expression in Tregs co-cultured with EBV (+) SNU719 and GT39 gastric cells than those co-cultured with EBV (−) AGS and BGC823 gastric cells, whereas no difference in CD62L expression was observed among the co-culture systems, regardless of EBV infection status.