We want to learn more about the influence of parents’ DNA on their children. An important aim of Child of the New Century is to look at children’s genes and their environment to see how they interact to affect health and development. Each child’s genes come from both their mother and father, so the value of the genetic information is increased greatly if we are able to look at both parents (if both are living in the household). Genes can have different effects depending on whether they come from the mother or father. DNA from parents will let us explore these differences. This is why – when looking at complex conditions such as asthma, obesity or diabetes – we need to look at DNA from parents as well as children.