CCND1 and esophageal squamous cell carcinoma: Similar to ESCC cell cultures (Figs. 2B–D, 3C, Supplementary Information, Fig. S5, S6), the GSK3β inhibitors significantly reduced tumor cell proliferation (Ki-67-positive cells), pGSS641 level and cyclin D1 expression, while inducing apoptosis (TUNEL- and c-PARP-positive cells) (Fig. 5, Supplementary Information, Fig. S8B).