BackgroundThe Cks1 protein is an essential factor in regulating cell cycle by mediating the ubiquitination of CDK inhibitor p27kip1. It has been reported that aberrant expression of Cks1 and p27kip1 proteins was found in various tumors and related to initiation and progression of carcinomas. However, the potential roles which Cks1 and p27KIP1 proteins play in NPC remain unclear. This study aims to examine the expression status of Cks1 and p27kip1 and their possible prognostic significance in NPC.