STAT4 and nasopharyngeal carcinoma: The selected genes in Cluster I (STAT4) and Cluster II (NBS1 and CYR61) were for distinguishing advanced NPC from early stage of NPC, whereas genes chosen from Cluster III (CDH4, CYLD, PI3, DSG3, and PTGS2) and Cluster IV (PRG1) were consistently dysregulated across all NPC samples investigated.