Knockdown of CBX3 suppressed the proliferation, migration and invasion of EC cells. (A) RT-q-PCR was used to evaluate the expression of CBX3 in EC cell lines compared to the normal esophageal epithelial cell line HEEC. (B,C) The knockdown efficiency of CBX3 in EC cell lines was verified by RT-q-PCR. (D,E) CCK8 and colony formation assays were applied to evaluate the effect of CBX3 depletion on proliferation of EC cells. (F,G) Effects of CBX3 silencing on EC cells migration and invasion were assessed by means of transwell assay. (H,I) Wound-healing assay was conducted to evaluate the effect of CBX3 silencing on migration of EC cells. Data are expressed as the means ± SD for n = 3. ** p < 0.01; *** p < 0.001.