P27 reduction notably reversed the RBM4-depletion induced ESCC cellular senescence as judged by the downregulated CDK4 and CDK6 in a western blot assay (Fig. 3a), and decreased β-gal positive cell numbers relative to RBM4 knockdown alone (Fig. 3b). Here, CDK6 is linked to esophageal squamous cell carcinoma.