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
To the Ends of the Earth
Science and Nature
Saving the Ocean
Science and Nature
Concussion: Answers in the Blood?
Science and Nature
Supercharge Your Brain: Maximizing Your Cognitive Abilities
Science and Nature
Animal IQ
Science and Nature
Turning the Tide
Science and Nature
Ancient Skies
Science and Nature
Infinite Series
Science and Nature
Fascinating Fails
Science and Nature
The Colorado
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.