Nevertheless, there is no conclusive evidence correlating cuticle thickness with plant resistance to different pathogens. In addition to the cuticle’s role as a physical barrier, there is growing evidence that its constituents may also act as pathogenesis signals for the invading pathogens and as triggers for the plant’s defense responses. The cuticle has also been recently suggested to play an active role in systemic acquired resistance-related molecular signaling. The precise set of events activated by cuticle components and degradation products in infected plant cells is still widely unexplored. Since the cuticle serves as one of the first lines of defense against invading pathogens, its permeability may affect plant resistance. Indeed, cutinase-overexpressing transgenic Arabidopsis plants and various Arabidopsis mutants altered in key enzymes for cuticle formation and structure, have all been shown to possess full immunity to some necrotrophic pathogens but not others. This was attributed to possible defects in the integrity of their cuticular layer, which led to high permeability of their cuticle and to the release of fungitoxic compounds?. The link between cuticle permeability and resistance to necrotrophic pathogens was further supported by observations in the Arabidopsis mutant lacerate. This mutant, with intermediate permeability as compared to lacs2, showed intermediate resistance to the necrotrophic fungal pathogen Botrytis cinerea, whereas the hothead mutant, with lower cuticle permeability, was as susceptible to B. cinerea as the wild type. Cuticle permeability was also linked to accumulation of reactive oxygen species, B. 
cinerea resistance and induction of innate immunity, yet the recently characterized resurrection 1 mutant, which has elevated levels of cuticular lipids but normal cuticular permeability, exhibits enhanced resistance to B. cinerea but enhanced susceptibility to the biotrophic fungus Erysiphe cichoracearum. The observed differences in the effects of permeable or altered cuticles on pathogenesis by diverse fungal pathogens suggest that other, yet to be discovered mechanisms may be involved in triggering the plant response and plant-induced resistance during cuticular disruption by invading pathogens. Embryonic stem cells are derived from the primitive ectoderm of the inner cell mass of blastocysts. They are characterized by their self-renewal capability and their pluripotency, i.e. they can develop into the three primary germ layers. Because of their capacity to differentiate into all cell types of the adult body, ES cells became a promising Ergosterol source for cell-based therapies for regenerative medicine over the past years. However, the application of differentiated pluri- or multipotent stem cells for these approaches carries a potential risk of tumor formation in vivo due to residual LOUREIRIN-B undifferentiated cells in the transplanted cell population. Hence, removal of residual undifferentiated stem cells from the differentiated cell Embryonic stem cells are derived from the primitive ectoderm of the inner cell mass of blastocysts. They are characterized by their self-renewal capability and their pluripotency, i.e. they can develop into the three primary germ layers. Because of their capacity to differentiate into all cell types of the adult body, ES cells became a promising source for cell-based therapies for regenerative medicine over the past years. However, the application of differentiated pluri- or multipotent stem cells for these approaches carries a potential risk of tumor formation in vivo due to residual undifferentiated cells in the transplanted cell population. Hence, removal of residual undifferentiated stem cells from the differentiated cell population.