<<Disclaimer: Verify this information before applying it to your situation.>> It is always helpful and interesting to hear from Dr. Murray. In his communication, re: refractory celiac disease he mentioned false negtive IGg results. (I.e., your test can come back false even if you are still ingesting some gluten). Forgive me if I am going over old ground, but I have a few questions that perhaps he (or someone else) can answer: 1. What is the percentage of false negative results? 2. Is there some correspondence between degree of deviatiion from a true gf diet and false negative results? 3. Is there some correlation between low susceptibility or asymptomatic disease and false negatives? 4. I am unclear about the difference between IGa and IGg - in other words, why did Dr. Murray specify false negative on the IGg but did not mention the IGa? Thanks so much - Mary Brown NYC