In all RET/PTC types the RET tyrosine kinase domain is fused to the N-terminus of ubiquitously expressed genes that is capable of ligand-independent dimerization.     ///    "What is more, the targeted expression of RET/PTC in mice leads to the development of thyroid tumors very similar to human PTCs. "    ///    RET/PTC3 seems to be associated with solid/follicular variant PTC and short latency period (it is found more frequently in children) whereas RET/PTC1--with classic PTC variant and long latency..     ///    The prevalence of RET/PTC in papillary thyroid carcinomas of thyroid varies widely from a few to about 80% with the highest frequency in tumors arising in children after ionizing radiation.     ///    Correlation with clinical outcome as well as prognostic value of RET/PTC is controversial.     ///    The majority of RET/PTC identified consists of two types which results from the inversion of chromosome 10: RET/PTC1 and RET/PTC3. 