This article is a commentary on the following study: "Ebbehøj NE, Meyer HW, Würtz H, Suadicani P, Valbjørn O, Sigsgaard T, and Gyntelberg F. Molds in floor dust, building-related symptoms, and lung function among male and female schoolteachers - The DAMIB study. Indoor Air 2005;15 (suppl 10):7-16"