1. Amgen Research, Oncology 1 , South San Francisco, CA, USA
2. Department of Genetics, Stanford University School of Medicine 3 , Stanford, CA, USA
3. Amgen Research, Research Biomics 2 , South San Francisco, CA, USA
4. Cancer Biology Program, Stanford University School of Medicine 4 , Stanford, CA, USA
5. Department of Pathology, Stanford University School of Medicine 5 , Stanford, CA, USA