Western blotting and qRT-PCR was employed to evaluate the expression levels of IMPDH1 and IMPDH2 protein and mRNA in NPC cell lines including CNE1, CNE2, C666, HONE1, and SUNE1, and an immortalized primary nasopharyngeal epithelial cell line (NPEC2 Bmi-1). This evidence concerns the gene BMI1 and nasopharyngeal carcinoma.