The sequencing of the first draft human genome more than 10 years ago delivered a “parts list” consisting of the genes that comprise human cells. The completed genome promised to revolutionize our understanding of a range of fundamental biological processes ranging from normal human development to the factors that drive development and progression of human disease. Today, we recognize that those early hopes were naïve, that biological systems are driven not by individual genes, but rather by complex networks of interacting factors that combine to define cellular phenotypes.
Two trends are driving innovation and discovery in biological sciences: technologies that allow holistic surveys of genes, proteins, and metabolites and the growing realization that analysis and interpretation of the resulting requires an understanding of the complex factors that mediate the link between genotype and phenotype. The growing body of biological and biomedical information, driven by an exponential drop in the cost of generating genomic data, provides an unprecedented opportunity for leveraging what we already “know” in a systematic way to understand the problems we are studying. Here, I will provide an overview “systems biology” approaches to understanding the complex networks that mediate cellular processes.