One effect of stress that is especially concerning to researchers is that some damage may be passed down to the next generation. Evidence is building that some epigenetic changes in gene expression can be inherited. For example, the children of mothers who had chronic stress during pregnancy have higher-than-normal rates of mood and behavior ailments as adults. The offspring of those who lived through a grave famine were found to have altered genes for obesity. These epigenetic effects, caused by stressful life events, have prompted researchers to explore what other stress damage may be inherited.