RET/PTC1 and RET/PTC3 are the most common types, accounting for >90% of all rearrangements.     ///    "RET/PTC1 tends to be more common in tumors with typical papillary growth and microcarcinomas and to have a more benign clinical course, whereas RET/PTC3 in some populations shows a strong correlation with the solid variant of papillary carcinoma and more aggressive tumor behavior. "