An exciting new domain for pattern discovery is the description of patterns of proteins or protein fragments expressed in a biological system that describes and predicts the state of the system. While an individual biomarker for a disease is an appealing idea, it is often the case that such markers are poor predictors of a disease state. Patterns of proteins and their metabolic products on the other hand can be far more sensitive and robust predictors, and will form the basis of future diagnostic tests as well as indicators of toxicity and efficacy in pre-clinical and clinical trials for new drug candidates.