How many are these patients? It's hard to tell, very difficult to tell, because in many surveys, we are always suffering from bias. There's always an intrinsic bias to any approach that we try to do to quantify this problem. I think in most estimates, people think about 10%, 15% of the patients will feel that they are unhappy with treatment of levothyroxine.

Now, it doesn't mean that only those have a problem. It means that in those patients, the problem reaches a certain threshold that makes them complain. I believe that if we think that this dissatisfaction, this syndrome of dissatisfaction with levothyroxine, is really caused by a change in combination therapy, extract to monotherapy, amount that we're giving, all patients are subject, because this is happening for all patients.

Now, it is possible that for the vast majority, it doesn't reach a level that bothers them sufficient to bring this to the doctors and say, well, my life is wrecked, because I'm on this thing now. But in certain patients, in about 10%, that's what happens.

They will tell you that they can't live their lives that they used to have before, and they are suffering. They're really suffering. People lose their jobs. People lose their marriages, major burden for their families. I see it in my office patients that come with the spouse. And the spouse is extremely frustrated, because we should be trying to do something for that patient. And we can't, and it's hard.

So again, the vast majority of the patients do very well on monotherapy. Whether or not they should be well, or whether or not they don't feel anything, they don't complain. So we assume they're OK. But this minority is very vocal and very unhappy.