In this design study we are collaborating with a group of genetic epidemiology experts who are using NGS data to study breast cancer. To understand our collaborators’ analysis needs we worked with this group for a year, spending four days a week in their lab. From numerous interviews, we developed over ten paper prototypes, five software prototypes, and acquired feedback. Analyzing this feedback revealed necessary visualization tasks and a workflow applicable to their data exploration. Our contributions are an articulation of a workflow and set of visualization tasks needed by our collaborators, and an early prototype of our system: compreheNGSive.