We talk with Ngozi Erondu, an assistant professor at the London School of Hygiene and Topical Medicine and co-founder of the Global Bridge Group. She is an infectious disease epidemiologist and global health policy expert. Her research looks at where "gaps" happen in health systems, things that might prevent people from receiving treatment if health workers don't have the resources they need.

We also hear from bestselling author Elizabeth Lesser. Her latest book, Marrow, is a memoir about the process Elizabeth and her sister Maggie went through when Elizabeth was the donor for Maggie's bone marrow transplant. She's also the co-founder of Omega Institute, a holistic education center.