For the first time since the Mayo Supreme Court decision of 2012, the Court of Appeals for the Federal Circuit (CAFC) in Exergen vs Kaz has ruled in favor of the patent eligibility of a medical diagnostic invention. While nonprecedential, this 2-to-1 decision is noteworthy for the guidance it provides to patent professionals seeking to protect diagnostic inventions. Specifically, it instructs that diagnostic methods may be eligible for patent coverage so long as they use unconventional methods for detecting analytes. Additionally, the Exergen decision offers another endorsement of the view put forth recently by the CAFC in Berkheimer v. HP and Aatrix v. Green Shades, that the inventive concept analysis that can arise in step-2 of the Mayo/Alice test is at least in part a factual question and not just a question of law. This factual vs legal debate continues to have reverberations throughout the patent law field, affecting both the manner in which courts conduct 101 examinations as well as the conclusions they reach.