According to the immunohistochemical results of 289 samples, compared with normal esophageal tissues, the total score of CDK1 staining intensity and cell percentage in ESCC tissues was obviously higher (3.540 ± 2.923 vs. 1.040 ± 1.632, P < 0.001; Fig. 1Q, Table S1). Here, CDK1 is linked to esophageal squamous cell carcinoma.