I have been searching my house endlessly ( 4 years now) looking for mold as I have high levels of both Ochratoxin A and Mycophenolic Acid. Our entire house has been torn up. My office is empty right now and we have torn out a wall to look inside....... and yet no sign of mold or water damage. I have been banging my head against the "literal" wall trying to figure this out and then it suddenly occurred to me that I have an issue in my office and in my bedroom. Both of those rooms have clay on the walls!!!! I have the HLA gene, the MTHFR gene and even the last gene that makes me one of the most sensitive to mold. It is a real thing.