Growing up alongside a twin brother, it never occurred to Joanne B. Weidhaas, M.D., Ph.D., that men and women might be treated differently. She could, she believed, do whatever she wanted to do. Perhaps this notion, which the chief of the breast cancer radiation service at Yale Cancer Center now admits might have been naïve, added fuel to Weidhaas’ ambitions to become a physician and a scientist.

Pursuing an M.D./Ph.D. at Tufts in 1991, she was charting relatively new territory there for both men and women. Only two classmates were pursuing the dual degrees, and few faculty had them. “I was feeling my way along,” Weidhaas said, noting that she wasn’t thinking about male or female role models. “It’s been more about finding a physician-scientist role model.”

Today, the associate professor of therapeutic radiology and mother of three has become a role model herself as she runs a lab, sees patients, and has founded a company, Mira Dx, with her colleague Frank Slack, Ph.D., professor of molecular, cellular, and developmental biology. When Yale M.D./Ph.D.s interviewing for residencies at Sloan-Kettering are asked to name a role model, says colleague Karyn A. Goodman, M.D., they name Weidhaas.

Weidhaas recently discovered a genetic marker for increased risk of ovarian cancer. Her findings, published in Cancer Research in July, report that the gene mutation KRAS-variant, present in 60 percent of hereditary breast and ovarian cancer patients tested, is associated with increased ovarian cancer risk and worse outcomes. Now Mira Dx markets a product, PreOvar, that can test for this biomarker in female relatives of breast and ovarian cancer patients who also have the marker.

Working with women’s cancers, Weidhaas says, “patients are happy I’m a woman.” However, when she was interviewing for internships 11 years ago, her mentor at Tufts, also a woman, warned her it was “not a level playing field.”

Pregnant with her first child, Lilly, Weidhaas decided, “It’s better to tell people I’m having a baby right at the beginning.” She had made a huge mistake, her mentor told her.

“Even if you’re 100 times better than someone else,” she recalled her saying, “they will take someone else because they just don’t know if you can handle it.” She realized her mentor had been right when, during her first interview, a department chair “freaked out” about Weidhaas’ pregnancy. She ultimately took an internship at Carney Hospital in Boston, where she was able to arrange three months off for the arrival of her daughter.

Weidhaas has juggled her many tasks by learning to do something she feels is difficult for women: to let go and get help. After her second child Drew, now 8, was born, she stopped running experiments and hired Sunitha Nallur to “be my hands in the lab.” She has a hand at home, too—Merle, their nanny of 10 years, whom Weidhaas describes as “an integrated part of the family.”

  Mornings, evenings, and weekends, Weidhaas, her husband, A.J., an attorney who is on the board of directors of Mira Dx, and their three children are “100 percent together. It’s all about family. We’re together no matter what we do.” When the physician/scientist is at work, though, she feels that her children understand that she is trying to make a contribution to the world.

“That’s been my hope, that we’ll find science that actually could make a difference for people now, not in a hundred years,” Weidhaas said. “To help prevent a cancer—or to at least best treat an individual’s cancer to give them the best chance for cure—it’s really the ultimate dream.”