CCDC6 and differentiated thyroid carcinoma: In papillary thyroid carcinoma (PTC), CCDC6–RET (RET/PTC1) and NCOA4–RET (RET/PTC3) account for ~90% of RET-positive cases, with breakpoints in RET intron 11, CCDC6 intron 1, and NCOA4 intron 8 [11].