The results have shown a significant increase in the percentage of Ki-67 positive cells (p < 0.01; Tukey’s multiple comparisons test) in thyroid tumors from either RET/PTC1TG;Patz1+/− or RET/PTC1TG;Patz1−/− mice, compared to those from RET/PTC1TG;Patz1+/+ mice. Here, RET is linked to thyroid tumor.