A strategy for a cross-species mouse and human genetic approach to identify susceptibility genes for anxiety disorders. The greatest advantages of using mouse models are the ability to reduce genetic heterogeneity and to control for the environment. The first step is to characterize aspects of a human disease in a mouse model, and to perform a search for candidate genes in a mouse model. It is then important to study these candidates in human populations to determine if they predispose to the disease under study. Mouse models are, however, needed to further characterize the function of the candidate genes, and to carry out potential drug target validation. Examples of candidate genes identified using different approaches in mice and humans are shown. Modified from .