We conclude that RET/PTC1 is the predominant rearrangement in PTCs from adults with a history of external irradiation in childhood.     ///    There was no association between the presence or absence of RET/PTC in the patient's tumor and clinical parameters.     ///    "Four of the PTCs contained RET/PTC1, confirmed by sequencing, and none contained RET/PTC2 or RET/PTC3. "    ///    RET/PTC and RET tyrosine kinase expression in adult papillary thyroid carcinomas.. 