HK1 and nasopharyngeal carcinoma: Bmi-1 was markedly upregulated in all the NPC cell lines we tested (CNE1, CNE2, HK1, HK1-EBV, SUNE1, HONE1, HONE1-EBV, 5-8F, NPC43 and C17) relative to NP69 nasopharyngeal epithelial cells (Figure 1A).