CCDC6 and medullary thyroid gland carcinoma: We selected TT and MZ-CRC-1 cells, that derive from human MTC harbouring the RET/C634W or RET/M918T mutation, respectively, and TPC1 cells, that derive from human PTC bearing the RET/PTC1 (CCDC6-RET) rearrangement [30–32].