My doctor has been using the CD57 test which measures a subset of natural killer cells to monitor my progress for over a year now. The first time I had it measured it was in the 30s. Then, shortly after I began the mB12 and methylfolate, it increased to the 50s. I just had it measured recently (I've been on the supplements for about a year now, same tiny, tiny, diluted speck of a dose) and the CD57 was in the low 80s. While I can't prove it, I believe that the supplements are responsible for the change. I remain more chemically sensitive now than I was before I started. I wish I could figure that out....it seems to be what's holding me back right now. But I love my energy levels! Thanks to all who have helped me get this far!