As a young teen in New York City, Juan Rivera was thinking about joining a gang. But his parents had a different plan for his future. They moved to New Jersey and sent Rivera to the Highland View Academy, a private high school in Maryland, where he met the chemistry teacher who would spark his interest in science.

Rivera credits his parents with putting him on a path that led to his tenured position at the National Institutes of Health, where he heads the Molecular Inflammation Section of the National Institute of Arthritis, Musculoskeletal, and Skin Diseases. "They had very little education," Rivera says of his parents, immigrants from Puerto Rico who never got past the elementary grades. "But they were wise enough to recognize that education was a way out."

Rivera considers that inspiring high school chemistry teacher as his first mentor. He would work under two more mentors after beginning his career at the NIH as a student trainee, a job he won through the government "Stay-in-School" program while an undergrad at the University of Maryland.

These days, Rivera believes one of his main duties at the NIH is as a mentor, particularly in helping minority scientists forge their careers. Counting those currently in his lab, Rivera has mentored about three dozen young scientists. What he's most proud of, he says, is the fact that all of his former protégés are still in research or medicine. "I think it's the responsibility of those of us who've received good mentoring to pay it back," Rivera says.

The mentor-protégé relationship is also one avenue toward increasing diversity in the sciences, according to Rivera. "This kind of thing is essential to identifying individuals who can succeed in science," he says, adding that he can also offer minority science students an example of someone who "didn't come from an advantaged background," yet succeeded.

Greg Gomez, who worked in Rivera's lab until last year, says he certainly learned from his mentor's example. "What he really believes is, science is not just a job," says Gomez, who's now an assistant professor of internal medicine/rheumatology, allergy, and immunology at Virginia Commonwealth University. "He's a very dedicated scientist, and the way I saw him conduct himself, he set a very good example."

Gomez says Rivera "helped solidify" his decision to stay in academia by encouraging him to question what he wanted to accomplish as a scientist. His goal, Gomez says, is to be an independent scientist.

Like Gomez, Rivera's other trainees have mostly gone into academia or industry. Job openings at the NIH, Rivera points out, are limited. The number of tenured Hispanic scientists at the NIH has grown over the past decade, from 17 in 1994 to 24 in 2004. Rivera was one of these, gaining tenure in 1999 after earning his doctorate from Catholic University. Still, minority groups remain underrepresented among NIH tenure-track and senior investigators, with African Americans, for example, now accounting for less than one percent of tenured scientists - down from years past.

Rivera says diversity is key in light of the NIH's charge to address health disparities among Americans. His own lab focuses on the dysregulation of inflammation in autoimmune and allergic responses; his work could someday affect systemic lupus, which disproportionately strikes black women.

Government, academia, and industry all have their roles in building a more diverse workforce, Rivera adds. "I certainly think that greater diversity is a good thing, regardless of the institution."