Caltech President David Baltimore, an outspoken Nobel laureate who led the once-insular university to become more diverse, more engaged in national affairs and more practical about the world around it, announced Monday he will step down in June after an eight-year tenure.
The 67-year-old biologist expects to stay at Caltech as a member of the biology faculty to pursue AIDS research with a $13.9-million grant largely supported by the Bill and Melinda Gates Foundation.
Baltimore's decision concludes a central chapter in one of the most remarkable comeback stories in the annals of American science.
He was tapped to take over the university in 1997 after years in exile from public life for his role in an acrimonious national controversy about research fraud that cost him the presidency of Rockefeller University in New York.
The decision of a Caltech faculty search committee and the board of trustees to offer Baltimore the presidency was a surprising institutional vote of confidence in a man more than one prominent scientist then considered tainted.
Baltimore said his intention to retire as president of the Pasadena-based university was not prompted by any health problem, budget deficit or management disagreements, but rather a sense that he had accomplished his goals as an administrator. "Caltech is a wonderful place, the best place to do science I have ever seen," Baltimore said. "I will have done what I can do [as president], and it is time for somebody else to be thinking about it. I have a fairly extensive life in science and in business that I will pursue."
Baltimore, easily among the most influential biologists of his generation, shared the 1975 Nobel Prize in Physiology or Medicine at age 37 for his work in virology and the discovery of the enzyme reverse transcriptase, used by the AIDS virus, among others, to replicate.
Paul Nurse, the Nobel-winning biologist who is president of Rockefeller University in New York, said it is a mark of Baltimore's ability that he produced 54 peer-reviewed research papers while president of Caltech.
"Carrying out research at this level is very difficult when you are pulled in so many directions," he said. "Yet he continues to be a great scientist."
Kent Kresa, chairman of Caltech's board of trustees, said a search committee for Baltimore's replacement would be organized by the end of the month.
As Caltech's seventh president, Baltimore took control of a school enormously prestigious among scientists but often ignored by the public because of its intense focus on pure research.
The university had largely depended on federal research grants, but Baltimore turned it increasingly to private support to fund its vision of scientific excellence.
"We have had to understand the role of commercialization and the interface with corporate development much more than in the past," Baltimore said. "That is something Caltech had ignored."
Under his leadership, Caltech recently raised more than $1.1 billion, including the largest single donation in the history of higher education.
In his own evaluation of his time as head of Caltech, Baltimore cited the gift of $600 million to the school by Intel Corp. co-founder Gordon Moore and his wife, Betty, as the "decisive moment" of his presidency.
Los Angeles philanthropist Eli Broad, a Caltech trustee and major school donor, said Baltimore was especially effective in reaching out to the broader community, to involve people not just in the affairs of Caltech but in the wider issues of science.
"He drew me in," Broad said. "David has the ability to understand where the world of science and medicine is going, and he can relate that in lay terms."
Baltimore worked to improve the quality of student life. In a school where there are more faculty in residence than undergraduates, student life was almost an afterthought.
He appointed the school's first full-time vice president for student affairs, improved student housing and started a $3-million student activities fund.
At the same time, Baltimore did more than any previous administrator to increase the diversity of the faculty and student body -- appointing women to many senior positions, including division head, vice president and chair of the faculty.
Slightly less than half of the undergraduate students and about a third of the graduate students are women.
Baltimore also reformed the school's administrative life, helped strengthen a faculty that received five Nobel Prizes during his tenure and, as one independent science educator said, gave the elite research center a sense of institutional purpose it had always lacked.
"He has made it much more of a place that has a plan and a vision about its own role and its own future," said Donald Kennedy, a former president of Stanford University who is now editor of the journal Science. "Plainly, Caltech has flourished. I dreamed he would have gone on forever."
Baltimore's outspokenness on pressing public issues of contemporary science gave a national profile to a traditionally introverted university.
"At the national level, his voice has lent visibility to the public discussion of scientific issues, including recombinant DNA and the AIDS epidemic," said MIT President Susan Hockfield.
Nobel laureate Harold Varmus, a former director of the National Institutes of Health who now heads the Memorial Sloan-Kettering Cancer Center in New York, said Baltimore's ability to speak his mind so openly about national controversies was a healthy sign for Caltech and a model for how other university leaders ought to behave.
"He has taken political stands that you can imagine some of his donors or board members might have found difficult, but that has not impaired his ability to run Caltech," Varmus said. "He has been very bold in his defense of science and the ways in which the current [Bush] administration may be limiting the country's scientific strength."
At key junctures in Baltimore's career, his willingness to speak his mind, coupled with the reluctance to compromise his principles, has been a blessing and, arguably, a curse.
As a young professor at MIT, Baltimore suspended the research that eventually earned him a Nobel Prize to devote himself to antiwar protests.
And, in one of the most contentious scientific disputes of the last 50 years, Baltimore refused to abandon a colleague accused of falsifying research data.
His part in the dispute began with arguments between co-workers over a research paper in the journal Cell by MIT biologist Thereza Imanishi-Kari. Baltimore was her most prominent collaborator and quickly became her chief defender as the dispute escalated into a bitter public clash over government probes of alleged research misconduct.
Although he was never directly accused of wrongdoing -- the work in question had not been performed in his lab -- Baltimore was singled out during congressional hearings into charges that important research findings had been fabricated.
Under the weight of public disapproval, his professional world collapsed.
The contested paper was retracted. Imanishi-Kari was charged by the National Institutes of Health with 18 counts of scientific misconduct. Baltimore resigned as president of Rockefeller University and returned to MIT, where he took refuge in research.
In 1996, however, Imanishi-Kari appealed. Three government administrative law judges threw out all the charges.
Within months, Baltimore was named to head the federal effort to develop an AIDS vaccine and appointed president of Caltech.
"No one was more surprised than me," Baltimore said.
Physicist Shirley Jackson, president of Rensselaer Polytechnic Institute in Troy, N.Y., and board chairman of the American Assn. for the Advancement of Science, said Baltimore led his school, in part, by the quality of his character.
"He has led a great institution of world-class scholars as a world-class scholar," she said.