I am an Assistant Professor in the Department of Neurological Surgery and Brain Tumor Research Center at UCSF. My lab uses novel computational and experimental strategies to study the molecular basis of cellular identity in the human brain in health and disease. Much of our work is motivated by a simple but powerful idea: by analyzing gene coexpression relationships in heterogeneous tissue samples, it is possible to isolate robust transcriptional signatures of distinct cell types and cellular processes in silico. More generally, we have found that the covariance structure of omics data contains an enormous amount of untapped information about the molecular and cellular organization of biological systems. We have developed a computational pipeline to extract this information and are applying it to samples from normal human brain samples and brain tumors. These efforts will produce mathematical definitions of neurobiological cell types under a range of conditions and reveal the critical molecular features that promote and maintain cellular identity in the human brain in health and disease.