Another interesting finding of our study was the observation that the cases with NIS membrane staining were predominantly wild type for the analyzed mutations (NRAS, BRAF and TERTp) (Table 3). Although this membrane expression was not associated with any outcome (clinicopathological features or prognosis), it is tempting to advance that the genetic background of tumors influence NIS targeting to the membrane. There are in vitro evidence that BRAFV600E mutation affects NIS targeting to the membrane (24), but the impact of the other mutations (NRAS and TERTp) remains unknown.