By targeting a conserved epitope and nucleotide sequence in LMP1 strain variants, the relative LMP1 levels were higher in the NPC xenograft (C15 tumor) compared with trace levels in cultured epithelial cell lines (293, NP460hTERT, HK1) infected de novo (Supplementary Figure 1A), indicating that even trace levels of LMP1 in stable NP460hTERT cells, comparable to the low levels in EBV-infected cultured epithelial cells, was sufficient to activate the induction of FAs. This evidence concerns the gene PDLIM7 and nasopharyngeal carcinoma.