CDKN1A and esophageal squamous cell carcinoma: Akt has been reported to regulate the stability of p21 by mediating phosphorylation at Thr145/Ser146 and relocation in cytoplasm.46 Though it appears that CYH33 possessed similar activity in inhibiting Akt phosphorylation in CYH33-sensitive and resistant ESCC cells, it’s worthwhile to further investigate the phosphorylation and location of p21 in CYH33-sensitive and -resistant cells.