From what I've read so far (not much), ATEOS had mild tinnitus since childhood. Could this be the autoimmune disorder that
@jer here is referring to? ATEOS said there could be made no doubts about the efficacy of the stem cells, since it could by no chance be a coincidence, seeing improvements in that tone so suddenly after so many years. He got another tone by (possibly) a hit to the ear some months before the treatment, and about 3 months after the treatment he saw improvements in that too. That tone could simply have resolved on its own by that time, coincidentally. Don't you think so?
Just to clear my point up; The stem cells likely fixed his immune system, ridding him off the tone he had had since childhood, and by 3 months the tone he got after the hit had coincidentally resolved naturally and with time, like a lot of cases of tinnitus do.
We have to weigh all this in before considering this.