Numerous studies have indicated that cyclic adenosine monophosphate, protein kinase A, and protein kinase C are involved in mediating NIS transcription activity [10], but Kogai et al. also reported that decreased NIS mRNA expression and NIS trafficking to the plasma membrane were found in differentiated thyroid cancers, which may be attributed to the activation of the insulin/phosphoinositide-3-kinase (PI3K)/Akt signaling pathway [11]. Here, SLC5A5 is linked to thyroid cancer.