TGFB1 and nasopharyngeal carcinoma: In conclusion, mechanisms of EBNA1 favor accumulation of Tregs in NPC through: (a) upregulated TGF‐β1 converted naïve T cell into Tregs; (b) upregulated CCL20 increased Tregs migration; and (c) polarized‐M2 macrophage converted naïve T cell into Tregs (Figure 6).