Shirley Tilghman, Princeton President, Says She Will Step Down The president of Princeton University, Shirley M. Tilghman, announced on Saturday that she would step down in June. Dr. Tilghman, a molecular biologist and a professor, became the second woman to lead an Ivy League institution when she emerged as the surprise choice to head the university in 2001. She made the announcement in an e-mail to Princeton students, faculty members, staff members and alumni. During her administration, Princeton also greatly increased its financial aid offerings, raising to more than 60 from 38 the percentage of students who receive it and more than doubling the amount that they receive. In addition, the Princeton campus underwent considerable transformation with several major construction projects, including a new residential college, a new library, the Lewis Center for the Arts and a neuroscience institute. In a statement, Kathryn A. Hall, the chairwoman of the board of trustees, praised Dr. Tilghman's "exceptional leadership for Princeton over these past 11 years, building on its distinctive strengths and pioneering important new initiatives in areas ranging from neuroscience, energy research and the arts to internationalization and campus life." She said that Dr. Tilghman, who has continued to teach during her time in office, would remain on Princeton's faculty, which she joined in 1986. Dr. Tilghman's departure comes at a time of transition on many Ivy League campuses. Dartmouth's president, Jim Yong Kim, recently stepped down; Yale's president, Richard C. Levin, is retiring at the end of this academic year. Brown University installed a new president, Christina Hull Paxson, this past summer. Dr. Tilghman, a distinguished researcher who was among the architects of the national effort to map the human genome and was an early advocate for women in a field still dominated by men, had originally been part of the search committee to choose a successor to Harold T. Shapiro, Princeton's 18th president, in 2001. She took office in June 2001, almost seven years after Judith Rodin of the University of Pennsylvania became the first female president in the Ivy League. Sam Wang, an associate professor of molecular biology and neuroscience, said Dr. Tilghman had "been able to lead in a way that - we've been through these good and these hard economic times, and things have been pretty collegial the whole time." Bruce Easop, the president of Princeton's undergraduate student government, noted her "sharp sense of humor." "What's really been remarkable is the candor with which she speaks about the university and her views, and the way her passion comes through," he said. After saying in an interview that "the board wishes she would stay forever," Ms. Hall added the next step would be to convene a search committee. She declined to discuss possible candidates. Dr. Tilghman plans to take a year off before returning to teaching. "I'm going to use next year to think about the ways I could be of service to the university, to the nation, as a volunteer," she said. I don't want to take on a full-time job anywhere but Princeton. Richard Pérez-Peña contributed reporting. Because of an editing error, an earlier version of this article incorrectly referred to the time Judith Rodin became the first female president in the Ivy Leagues. It was 1994, not 2001.