Networks are a fundamental tool for understanding the intricate interconnections that govern biological systems. This talk will describe two ways in which networks, in combination with mathematical models and algorithmic techniques, can yield valuable biological insights.

Causal regulatory networks help reveal the hidden regulators of gene expression patterns. To facilitate their analysis we established an efficient method for evaluating the significance of the overlap of ternary signals, which generalizes Fisher's exact test. We used this method to analyze a large-scale causal regulatory network and uncovered new regulators of cardiac hypertrophy.

Metabolic networks help identify novel drug targets. We uncovered structural features of these networks that had been missed by previous researchers, and developed a theoretical framework based on duality for analyzing them in a consistent fashion. We used this theoretical framework to create a new metabolic network for Mycobacterium tuberculosis by algorithmically merging two existing networks, and identified several putative drug targets.