We also found IL-17-secreting T clones highly expressing Foxp3, and with the suppression function to naïve T cells from NPC TIL in vitro (unpublished data), the failure to find the double IL-17 and Foxp3 positive TIL in NPC may be due to the lack of sensitivity of the IHC staining method or the differences between in vivo and in vitro conditions. This evidence concerns the gene IL17A and nasopharyngeal carcinoma.