We use genomic systems biology to model
regulatory and enzymatic networks in mammalian and microbial cells. We develop technologies based on DNA-arrays, mass-spectrometry, automated microfluidics, polonies, and homologous recombination genome engineering. We have used these to discover genes affectng cell proliferation, alternative RNA splicing, and new regulatory sites involved in cell-cycle control and stress responses. We have developed integrated gene expression and functional genomics databases. For additional information see arep.med.harvard.edu.