Rebecca Davis

"You must leave now," thousands of Americans from Puerto Rico to Oregon to Florida, Montana, Texas and beyond were told, as floods, fire and wind threatened their lives. Some said no.

In Leipzig, Germany, two scientists from very different backgrounds are working on a unique research project.

Carmen Bachmann, a professor in Leipzig, is building an online network to help political refugees who are scientists or social scientists connect with professional peers in Germany — their new home.

Melanoma can be a deadly skin cancer, but 10 years ago, biologist Jim Allison figured out a way to tweak the body's immune system to go after those malignant cells. Some patients are now cancer-free.

When Jimmy Carter said his advanced melanoma was gone, he credited immunotherapy, treatments that harness the immune system to fight cancer cells. This idea dates back to a 19th-century doctor.

She's a typical teen — blue nails, loves Coldplay. But she believes she won't be able to build a life in her homeland.

Fatmeh is one of hundreds of thousands of children who have fled Syria with their families. In Lebanon, she works in the fields up to 14 hours a day, clinging to her dream of going to college.

One of the most important medical advances may also be the simplest: hand-washing. It's the best defense against spreading disease. And its power was discovered long before anyone knew about germs.

If you think that an artificial eye looks like a big glass marble, you're not alone. And you're wrong. We visit the people who made a prosthetic eye for a 5-year-old boy who lost an eye to cancer.