It’s a basic principle of immunology: When a germ invades, the body adapts to that particular target and destroys it. But much remains unknown about how the immune system refines its defensive proteins, called antibodies, to most effectively zero in on that invader. Experiments at The Rockefeller University offer new insight into the details of this selection process.

In research published in Science on July 16, scientists led by Michel Nussenzweig, Zanvil A. Cohn and Ralph M. Steinman Professor and head of the Laboratory of Molecular Immunology, uncovered a new mechanism by which the B cells that produce the most finely tuned antibodies rise to dominance. This discovery builds on earlier work published last year.

Blood hormone tests predicted a woman’s risk for developing postmenopausal breast cancer for up to 20 years, according to data from the Nurses’ Health Study presented at the 11th Annual AACR International Conference on Frontiers in Cancer Prevention Research, held in Anaheim, Calif., Oct. 16-19, 2012.

“We found that a single hormone level was associated with breast cancer risk for at least 16 to 20 years among postmenopausal women not using postmenopausal hormones,” said Xuehong Zhang, M.D., an epidemiologist at Brigham and Women’s Hospital and an instructor in medicine at Harvard Medical School in Boston, Mass. “We, and others, are now evaluating if the addition of hormone levels to current risk prediction models can substantially improve our ability to identify high-risk women who would benefit from enhanced screening or chemoprevention. If so, the current data suggest that hormone levels would not need to be measured in the clinic more than once every 10, or possibly 20, years.”

A new study from Lund University in Sweden shows that women with low levels of an anti-stress hormone have an increased risk of getting breast cancer. The study is the first of its kind on humans and confirms previous similar observations from animal experiments.

The recent findings on a potential new marker for the risk of developing breast cancer are presented in the Journal of Clinical Oncology. The study focused on a hormone which circulates freely in the blood, enkephalin, with pain- and anxiety-reducing properties. Enkephalin also reinforces the immune system by directly affecting immune cells.