1. Department of Statistics and Operations Research The University of North Carolina at Chapel Hill Chapel Hill 27599 North Carolina USA
2. Department of Biostatistics The University of North Carolina at Chapel Hill Chapel Hill 27516 North Carolina USA
3. Department of Genetics The University of North Carolina at Chapel Hill Chapel Hill 27599‐7264 North Carolina USA
4. Carolina Center for Genome Sciences The University of North Carolina at Chapel Hill Chapel Hill 27514 North Carolina USA
5. Lineberger Comprehensive Cancer Center The University of North Carolina at Chapel Hill Chapel Hill 27514 North Carolina USA