Dr. Simon retired as director of the Biometric Research Program and as chief of the Computational/Systems Biology for the Division of Treatment and Diagnosis of the National Cancer Institute (NCI). In addition to overseeing the NCI genomics and drug development program, he provided leadership for an active research program in computational and systems biology applied to development of new therapeutics and immune-modulating regimens, discovery of molecular and antigenic targets and development of companion diagnostics. He hired and provided leadership for development of bioinformatic systems which empower biologists to creatively utilize genomic data in development of improved treatments for cancer. He led a team of computational and systems biologists who develop methods for elucidating the process of oncogenesis from deep sequencing data and conduct analyses of pre-clinical pharmacologic experiments to understand resistance mechanisms and develop effective combination regimens. He also conducted a post-doctoral training program in computational and systems biology with a focus on preparing computational and biological scientists. 

He received his D.Sc. in applied mathematics and computer science from Washington University in St. Louis.