Dr. David Gozal is considered a pioneer for his work researching and treating sleep disorders in children.
But some of his most recent research highlights the grave consequences on the immune system when we get too little sleep.
In the clip above from the National Geographic channel's "Sleepless in America" documentary, Gozal explains an experiment where scientists injected two groups of mice with cancer cells. One group was allowed to sleep normally, while the other group was disrupted throughout the night. In the mice with disrupted sleep, the cancer grew twice as fast.
"We need to respect sleep," he says in the clip. "We need to make sure that sleep is part of our culture."