Defend
Look at a nature survivalist, rancher twins, a doctor who survived Ebola and the recipient of a cutting-edge cancer therapy to uncover the wildly advanced biology that keeps us alive against all odds.
Previews + Extras
Episode 4 Preview | Defend
S1 E4 - 30s
Look at a nature survivalist, rancher twins, a doctor who survived Ebola and the recipient of a cutting-edge cancer therapy to uncover the wildly advanced biology that keeps us alive against all odds.
The Immune System
S1 E4 - 2m 6s
An introduction into the amazing functions of the human body's immune system.
Similar Shows

The Himalaya Connection
Science and Nature

The Invisible Shield
Science and Nature

The Gene
Science and Nature

Humanity from Space
Science and Nature

Evolution Earth
Science and Nature

Greta Thunberg: A Year to Change the World
Science and Nature

The Brain-Gut Connection with Dr. Emeran Mayer
Science and Nature

Insecta: Science that Stings
Science and Nature

Mysteries of Mental Illness
Science and Nature

Changing Seas
Science and Nature
WETA Passport
Stream tens of thousands of hours of your PBS and local favorites with WETA Passport whenever and wherever you want. Catch up on a single episode or binge-watch full seasons before they air on TV.