Seung K. Kim was born in Seoul, South Korea, the oldest of three boys. His father had escaped North Korea at the beginning of the Korean Conflict, and he eventually became a doctor. His mother was from a large family in Seoul; she was a pharmacist, owning her own pharmacy. When Kim was about two his father took a job in a hospital in Johnson City, New York; he then accepted a position at the University of Pennsylvania. The family arrived when Kim was about three. They were intending to return to South Korea when Kim's father finished his radiology training, but visa uncertainty due to the Vietnam War caused them to decide to stay here. Kim began school in a Roman Catholic school in Philadelphia, but the family moved back to Johnson City when Kim was in second grade. They spent two years there before moving to Vestal, a suburb of Binghamton. Kim was, he says, obsessed with baseball, playing and reading about it. He also began to go fishing with his father, who had liked to fish in Korea. Fishing also provided Kim with an experiment for his seventh-grade science class. His teacher for that class was influential, by taking Kim seriously and by encouraging him. Mr. Jason, the science teacher, even told Kim's father that he thought Kim could go to Harvard, which was, as Kim says, "the Everest" of colleges in his father's mind. A friend who went to Phillips Exeter Academy told Kim about the school at Thanksgiving, and Kim spent the rest of the school year persuading his parents to send him there and then having to go through the application process. He was accepted and began three of his happiest years when he was a sophomore. He had finally found an academic atmosphere that suited and challenged him, and he loved it. He especially loved math and his math teachers, but he also began to discover experimentation, one summer designing for himself a chemistry experiment to work on when he began school in the fall. He talks here about a number of his teachers who were excellent and whom he still remembers by name. He entered Harvard University, which he found large, anonymous, and somewhat disappointing after Exeter, until he had a biochemistry class taught by Mark Ptashne, Tom Maniatis, and Douglas Melton. Here Kim talks about his college laboratory experience with Richard Goldstein; the process of writing; and his summer tour-guide job in Paris, a job that showed him how much he liked to lecture. He describes his tutelage under James Rheinwald at the Dana-Farber Cancer Institute; his exposure to the literature and history of his field of research; and his decision to pursue a career in medicine. Kim applied to medical school and became discouraged by the interview process. Urged by Goldstein, he accepted a late interview invitation from Stanford University, where he met Stanley Cohen. He found California beautiful and decided to attend Stanford. There he entered the MD/PhD program and worked in Dale Kaiser's biochemistry laboratory studying cell signaling during development. He discusses his experiences in the MD/PhD program at Stanford; his interest in oncology; and his residency at Brigham and Women's Hospital. On his first day as an intern he met the woman who became his wife. He accepted a fellowship at the Dana-Farber Cancer Institute; and then he did a postdoc on pancreas development in Douglas Melton's lab. He goes into great detail about his wife's career, also in medicine. Next he talks about his collaboration with Matthias Hebrok and his research on pancreas development. He accepted a position at Stanford University in developmental biology and set up his lab. He explains his laboratory management style and his role in the laboratory and goes on to talk about his administrative duties; the personnel make-up of his lab; and how he sets the research agenda of his laboratory. He continues with a discussion of his current research using three model systems to study pancreas development and function and insulin production; the practical applications of his research; the issue of patents; balancing family and career; the percentage of women and minorities as graduate students and principal investigators; and the process of writing journal articles. Kim concludes his interview with lessons he has learned; his reasons for becoming a principal investigator; and the qualities of a good scientist.