Women who are conceived when their father is overweight could be at a 30% higher risk of developing breast cancer, new research suggests. Scientists at Georgetown University in Washington DC found that obese male mice which mated with normal weight females produced female pups that had an increased chance of developing breast cancer than pups from non-obese fathers.The researchers found evidence that obesity changes the miRNA signature, or epigenetic regulators of gene expression, in both the father mouse's sperm and the daughter's breast tissue, suggesting that miRNAs may carry epigenetic information from obese fathers to their daughters.The miRNAs the scientists identified regulate insulin receptor signalling, which is linked to alterations in body weight and other features associated with cancer development, such as hypoxia.Maternal obesity is believed to influence breast cancer in humans, however up till now little research has investigated the influence of overweight fathers. ..