IGF1 and nasopharyngeal carcinoma: Previously, EBERs were reported to induce IGF-1 in the EBV-positive C666-1 NPC cell line and in EBER-transfected NPC-derived EBV-negative CNE1 and HONE1 cell lines (10), as well as in EBER-transfected gastric carcinoma NU-GC-3 cells (9).