Identifying causal genes underlying susceptibility to human disease is a problem of primary importance in the post-genomic era and in current biomedical research. Recently, there has been a paradigm shift of such gene-discovery efforts from rare, monogenic conditions to common "oligogenic" or "multifactorial" conditions such as asthma, diabetes, cancers and neurological disorders. These conditions are referred to as multifactorial because, susceptibility to these diseases is attributed to the combinatorial effects of genetic variation at a number of different genes and their interaction with relevant environmental exposures. The goal of this book is to introduce gene prioritization aspects and the candidate gene prioritization algorithms to give readers a comprehensive view on the subject.