Volatile organic compounds (VOCs) released by fungi, especially the well-known “mushroom alcohol” 1-octen-3-ol, do far more than give mushrooms their earthy smell. These compounds influence ecosystems by promoting or inhibiting plant growth, defending crops against pathogens, and mediating interactions between fungi, plants, and insects. In humans, fungal VOCs have been linked to immune responses and even potential health risks at high concentrations.