Recently, we have developped a yeast-based (Saccharomyces cerevisiae) assay to isolate drugs active against mammalian prions. The initial assumption was that mechanisms controlling prion appearance and/or propagation could be conserved from yeast to human, as it is the case for most of the major cell biology regulatory mechanisms. Indeed, the vast majority of drugs we isolated as active against both [PSI+] and [URE3] budding yeast prions turned out to be also active against mammalian prion in three different mammalian cell-based assays. These results strongly argue in favour of common prion controlling mechanisms conserved in eukaryotes, thus validating our yeast-based assay and also the use of budding yeast to identify antiprion compounds and to study the prion world.