MI differentiation after (A) single CTN, OTA or STER administration, (B) CTN, OTA and STER co-administration. All treatments were tested in three independent experiments and approximately 12,000 nuclei were scored for each treatment. PRI differentiation after (C) single CTN, OTA or STER administration, (D) CTN, OTA and STER co-administration. All treatments were tested in three independent experiments and approximately 500–600 metaphases were scored for each treatment. STER and STER-co-treatments at 10−6 M were highly cytotoxic. Bars represent mean ± SEM. The asterisks indicate statistically significant differences over the respective vehicle-treated cells (p < 0.01).