Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu|Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu|Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu|Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu|Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu|Medical Scientist Training Program, Stanford University, Stanford, CA 94305, USA. kasson@cmgm.stanford-edu