Immunofluorescent breast cancer cells used in this study. Sometimes, the silencing of a gene is as important as its activation. Nonetheless, up to now, most studies on hormone-mediated gene regulation have focused on researching the factors that influence the activation of certain genes. Little attention has been paid to gene silencing.

A new study has found that the little-known member of the human herpesvirus family called HHV-6A infects the lining of the uterus in 43% of women with unexplained infertility but cannot be found in uterine lining of fertile women. The study was conducted by investigators at the University of Ferrara, Italy.

Researchers at McMaster University have established a way to harness DNA as the engine of a microscopic "machine" they can turn on to detect trace amounts of substances that range from viruses and bacteria to cocaine and metals.

Since the 1970s, U.S. doctors have prescribed lithium to treat patients with bipolar disorder. While the drug has a good success rate, scientists are still unsure exactly how it achieves its beneficial effects.