 RET/PTC1 chromosomal rearrangement is associated with papillary thyroid carcinoma formation in children exposed to ionizing radiation.     ///    "Only one line had thyroid-targeted, doxycycline-regulated RET/PTC1 and luciferase coexpression, in which doxycycline induction of RET/PTC1 led to Erk phosphorylation and reduced expression of the sodium/iodide symporter (NIS). "    ///    "In this study, we aimed to create a doxycycline-inducible mouse model of thyroid RET/PTC1 and luciferase reporter gene coexpression to allow for noninvasive monitoring of transgene expression in mice of various ages and timepoints after induction. "    ///    We found that acute RET/PTC1 expression can activate the MEK/Erk pathway and downregulate NIS expression in the mouse thyroid gland.     ///    "However, a higher level of RET/PTC1 is likely necessary for tumor formation. "    ///    Creation and characterization of a doxycycline-inducible mouse model of thyroid-targeted RET/PTC1 oncogene and luciferase reporter gene coexpression..     ///    "Transgenic mice carrying the rtTA gene driven by the thyroglobulin promoter were generated, and crossed with responder mice carrying RET/PTC1 and firefly luciferase genes under control of a bidirectional tetracycline response element. "    ///    We previously created a transgenic mouse model with thyroid-targeted constitutive RET/PTC1 expression and demonstrated papillary thyroid carcinoma formation. 