Thymine DNA glycosylase (TDG)‐KO‐mediated tumor suppression is reversed by transcriptional coactivator with PDZ binding domain (TAZ) overexpression. A, Proliferation curves of cells expressing control vector, lentivirus containing shRNA against TDG (shTDG), and shTDG + TAZ. B, C, Colony formation assays (B) and invasion assays (C) of cells expressing control vector, shTDG, and shTDG + TAZ. Representative pictures are shown on the left, and quantification histograms on the right. D, Cell surviving fractions of cells expressing control vector, shTDG, and shTDG + TAZ under irradiation. E, γ‐H2AX levels in cells with shTDG and shTDG + TDG 6 h post‐irradiation. F, G, mRNA (F) and protein (G) levels of PRKDC, TP53BP1, and XRCC6 in cells with shTDG and shTDG + TDG. H, Model of TDG‐regulated TAZ in tumor progression and radioresistance in esophageal cancer. *P < .05, **P < .01, ***P < .001, ****P < .0001. EV, empty vector; Me, methylation; NHEJ, nonhomologous end joining; ns, no significance; shScr, lentivirus containing scramble shRNA; TAZ, plasmid containing TAZ; TDG, plasmid containing shTDG‐resistant TDG