For example, 172 patients (72.9%) with stage II NPC (T2N0 or EBV DNA–negative T1-2N1) in the current TNM staging system were relegated to RPA stage I, whereas 342 patients (28.9%) with stage III NPC (T3N0 or EBV DNA–negative T3N1) were relegated to RPA stage I. On the contrary, T4 is an adverse factor regardless of the N category, as is N3 irrespective of the T category. This evidence concerns the gene RPA1 and nasopharyngeal carcinoma.