Interestingly, we found that four out of five NPC-PDXs had CNV gain of cyclin D1, (CCND1, chr11-q13), and three NPC-PDXs had CNV loss of cylin-dependent kinase inhibitor 2A, (CDKN2A, chr9-p21). This evidence concerns the gene CCND1 and nasopharyngeal carcinoma.