Wilhelm Hansberg obtained an MD degree at the Universidad Nacional Autónoma de México, UNAM. He obtained an MS and a PhD in Biochemistry at the Faculty of Chemistry, UNAM before studying cell differentiation in chicken reticulocytes and thereafter xenopus oovogenesis at the Consiglio Nazionale delle Ricerche, Rome, Italy. He is now a professor at the Instituto de Fisiología Celular, UNAM, where he investigates cell differentiation in micro-organisms as a response to oxidative stress, using mainly Neurospora conidiation as a model system. He took a two-year leave to complete work at the Heinrich Heine University, Dusseldorf, Germany, studying reactive oxygen species in Neurospora. He is also interested in i) the structure–function relationship of antioxidant enzymes, mainly catalases, using crystallography and molecular dynamics, and ii) mathematical modeling of cell differentiation.