Researchers discovered a new fungus called Mucor germinans that infected a cancer patient’s lungs and appeared as yeast cells rather than the typical thread-like fungal structures. This is unusual because Mucor infections normally show filamentous hyphae, and the yeast-like appearance made it look like a different fungus, potentially delaying correct diagnosis and treatment. The study shows that this fungus can change forms depending on temperature and other conditions, and identifying it requires checking for multiple nuclei in the cells to distinguish it from other similar-looking yeasts.