In this study, we found that both CDK5 and p21 were downregulated in cancer tissues compared with normal side, and lower CDK5 expression was significantly associated with advanced TNM stage (p = 0.042), and Fuhrman grade (p = 0.035), lower p21 was significant associated with Fuhrman grade (p = 0.026) either. Here, CDKN1A is linked to cancer.