my name is mary mcgrath. i'm the senior director of structural chemistry here at gilead sciences. our goal at gilead is to get safe and effective drugs to patients sooner. in the field of crystallography, symmetry is very important. symmetry tells you how each molecule in the crystal is related to the other molecules. so we need to know that information in order to get out our final picture of what our protein looks like. it's also very important in just trying to complete our experiments successfully. we need to know those relationships. what we end up doing is using math as a lens to refocus our image. when we are able to provide a picture in crystallography of the protein target to the chemists, they are able to specifically design for that protein. so what ends up happening is you accelerate the drug discovery process. instead of taking ten years to come up with a potent compound, maybe now it would take three or four years. our process has many parts to it, and one of the things i really love about being a protein crystallographer and doing structure-guided drug design is tha