Furthermore, we observed that overexpressed CDK4 was positively associated with tumor clinical stage (I-II vs. III-IV) (p = 0.047), but not correlated with patient's age, sex, smoking, lymph node metastasis (N classification), tumor size (T classification), and distant metastasis (M classification) in NPC (Table 2). The gene discussed is CDK4; the disease is nasopharyngeal carcinoma.