Nt four means we have four eyed atoms attached onto that particular hormone. Now, T three and T four are both lipid soluble. So that means they do not dissolve in water, so they do not dissolve in our blood and they require protein carriers to basically carry them within our bloodstream. Now, this also means that T three and T four, because they are lipid soluble, they can easily dissolve across our cell membrane. And that means they basically enter the nucleus of our cell that targets out, and they influence our cell on a transcriptional level. So they basically affect the different processes in our body, especially protein synthesis.