RET/PTC fusion gene rearrangements in Japanese thyroid carcinomas..     ///    "RET rearrangements are restricted to a well-differentiated papillary carcinoma, suggesting that RET/PTC positive papillary carcinomas do not progress to undifferentiated carcinoma.. "    ///    "However, the reported prevalence of RET/PTC activation in papillary carcinoma was variable, and the clinical relevance of RET/PTC rearrangements in papillary carcinomas is still controversial. "    ///    The prevalence of RET/PTC activation in papillary carcinoma among the Japanese population was higher than in previous reports. 