Family-Based QTL Mapping is a way to look at genes in families and try to find out which ones might be related to certain traits. We look at families because it helps us identify which genes might be related to certain traits more easily. When we look at families, we can look at how traits are passed down from one generation to the next, which can help us figure out which genes might be related to those traits. It can also help us understand why some people in a family might have a certain trait, and others might not.