Physicians and patients expect laboratory tests to produce the same results, regardless of where they are performed. Unfortunately, that’s not always the case, even for FDA-approved assays. As the current chair of the College of American Pathologists committee for accuracy-based proficiency testing, Dr. Andy Hoofnagle is an authority on this industrywide problem. In this interview, he explains the root causes of inconsistent results across platforms, and how manufacturers, regulators, and professional societies might work together to solve it.