Disease gene expression profiles can be utilized as biomarkers for diagnostic, prognostic, and targeted therapeutic purposes, although individual data sets may be of limited generic value. To develop broader clinical relevance from disease gene signatures, Inkeles et al. demonstrate how mining publically available microarray data from a range of skin disorders can elucidate disease pathways, generate a multi-disease classifier, and identify potential therapeutic targets. This integrative molecular classification and functional analysis offers a new approach to understanding disease pathogenesis, with significant implications for diagnostics and the development of personalized medicine.