γH2AX foci levels. (A) Quantification of γH2AX foci per cell in knockout iPSCs with the indicated genotypes. (B) Patient-derived iPSCs treated or not with DOX-induced expression of ADH5. The points represent the number of foci per nucleus in a single cell. Cells were exposed to formaldehyde (HCHO; 5 μM) for 24 hours and stained with anti-γH2AX antibody. Mean ± SEM (n = 500) are shown for each condition. The experiment was repeated twice with similar results. The P values were calculated using 1-way ANOVA with Tukey’s multiple-comparisons test. Representative images are shown. n.s., not significant.