the disease. A combined p-value method can be used for quantitative analyses, but this approach may present its own challenges. The individual data sources may not be weighted equally since the relative magnitudes of the p-values can be vastly different across platforms (e.g., mouse and human QTL studies). To avoid such issues, qualitative scores that measure the presence or absence of evidence above a threshold may be used, but thresholds have their own problems. Regardless of scoring choice, and despite some problems associated with each, a combined gene rank score can be generated from data integration. These gene rank scores can be used to perform weighted analysis or to define gene subsets for further investigation.
