The budding yeastSaccharomyces cerevisiaepossesses a very flexible and complex programme of gene expression when exposed to a plethora of environmental insults. Therefore, yeast cell homeostasis control is achieved through a highly coordinated mechanism of transcription regulation invol-ving several factors, each performing specific functions. Here, we present our current knowledge of the function of the yeast activator protein family, formed by eight basic-leucine zipper trans-activators, which have been shown to play an important role in stress response