RET and thyroid gland papillary carcinoma: In a series of 26 papillary thyroid cancers that occurred in highly contaminated children in Ukraine, kinase fusion oncogenes resulting from intra-chromosomal rearrangements that activate the mitogen-activated kinase pathway (MAP kinase pathway) were found in 23 (including RET/PTC, BRAF, and TRK rearrangements), and BRAF (n = 2) and TSHR (n = 1) gene point mutations were found in only 3 tumors (36).