Rare diseases are notoriously hard to pin down — patients often spend years bouncing between specialists. Researchers writing in Nature describe an AI system that takes on these puzzles and, crucially, lays out traceable reasoning for how it reaches each diagnosis.

That transparency is the point: rather than a black box spitting out an answer, doctors can follow the AI's logic, check it, and trust it — turning the technology into a genuine partner in the search for an explanation.