Since the enhanced expression of hTERT is observed in most cancers and the expression of BMI-1 has been reported in various types of cancer, including squamous cell carcinoma [29], we decided to test one of the newly established cell lines for the ability to induce tumors in an immunodeficient mouse model, but no tumor formation was observed (Figure 9A). Here, BMI1 is linked to squamous cell carcinoma.