Previous work has suggested that problems with placental development might lead to congenital heart defects. However, little is known about the mechanisms that might underpin this relationship between the placenta and the heart. A new paper in Development leverages conditional mouse knockouts to explore this link in detail. To learn more about the story behind the paper, we caught up with first author Wenli Fan and corresponding author Zhongzhou Yang, a Professor at Nanjing University Medical School, China.