Ras and many other proteins that are oncogenic, i.e., associated with cancer when mutated, are allosteric switches. The growing power of gene synthesis and next-generation sequencing can be harnessed to yield insights into molecular mechanism in a novel way. I will cover the application of high-throughput mutagenesis to Ras, combined with structural analysis and molecular dynamics simulations, with an emphasis on understanding the allosteric mechanisms that lead to mutational sensitivity.