CCND1 and nasopharyngeal carcinoma: While the level of over-expression of cyclin D1 (26%) in recurrent NPC specimens was similar to the levels of over-expression (30%[7] to 66%[9]) found in primary untreated NPC, the lack of expression of p16 in recurrent NPC specimens (96%) was significantly higher than those typically reported for primary untreated NPC (40% to 70%) [9-12].