Potential mechanisms of COS resistance resulting from the overexpression of specific genes identified in this study. In this model, ERG24 overexpression would reduce membrane permeability by altering the composition and fluidity of the plasma membrane. ARL1, BCK2, MSG5 and RBA50 either alone or in combination, could detect COS binding to the membrane and subsequently induce transcriptional and additional changes that reduce membrane permeability. Overexpressing these strains that are resistant to COS results in a down regulation of transcripts related to energy production (e.g. ATP synthesis and mitochondrial activity; examples of specific down-regulated genes are listed in the blue boxes). A large number of genes involved in cell division (mitosis and meiosis), cell cycle and cytoskeleton are transcriptionally up-regulated in the COS resistant overexpression strains (examples listed in the orange boxes). Integrin refers to yeast proteins that have properties similar to a mammalian integrins.