A persister subpopulation has also been demonstrated in budding yeast Saccharomyces cerevisiae. Yeast persisters are triggered in a small subset of unperturbed exponentially growing cells by spontaneously occurring DNA damage, which leads to the activation of a general stress response and protection against a range of harsh drug and stress environments. As a result of the DNA damage, yeast persisters are also enriched for random genetic mutations that occurred prior to the stress, and are unrelated to the stress survival.[21]