In the 1980s, Stephen Crohn was exposed to HIV but never became infected. Throughout his lifetime, he helped scientists discover a genetic mutation that keeps HIV from infecting the immune system. Crohn died in August at age 66. A doctor who worked with him reflects on his contributions to science and the fight against AIDS.
The U.S. poverty rate has remained at about 15 percent for the third year in a row. Despite signs of an improving economy, getting out of poverty continues to be a challenge for many Americans.
A prominent Russian lawmaker mocked the U.S. during the mass shooting in Washington this week. But statistics show that Russia has more killings each year than the U.S. despite a much smaller population.
A chance for families in South and North Korea to meet long-lost relatives has been put off, as North Korea canceled reunions that were to take place in the coming week. A South Korean official called the decision "inhumane" Saturday.