FOXP3 and nasopharyngeal carcinoma: In our study, the ratio of CD8+TIL to Foxp3+TIL (CTL/Treg cells) was significantly associated with poor OS and PFS in early stage patients (Fig 3A), but had no effect on late stage patients, implying that increased number of Foxp3+Treg cell together with decrease number of CD8+CTL could suppress tumor growth and lymph node metastasis at the early-stage of NPC (high CD8+TIL number is positively associated with N stage in Table 3).