What happens when you tick off that little box at the DMV to sign up as an organ donor? Absolutely nothing until you are truly dead and no longer need your body parts, DNews explains.

“A breathing body with a heartbeat is difficult for many families to accept as a cadaver,” host Jules Suzdaltsev says, which could deter organ donation. Additionally, the majority of people get their information about organ donation through television shows and their friends.

Read: 7 Body Parts You Can Live Without

But many parts can be transplanted — the heart, kidneys, liver, lungs, pancreas, intestines, skin, bone tissue, corneas, tendons, ligaments and blood vessels — and offer a second chance to others.

Every day people die while waiting for donated new organs. There are almost 120,000 on a list for transplants, but few people die in a manner that lends itself to donation.

donors-per-million Spain appears to lead the world in the proportion signed up to donate their organs after death. DNews

Donated organs may also be declined, for a number of reasons: An organ may be too old, not a proper size or be infected with HIV or an active cancer.

According to DNews, for the deceased donor, once the organs are removed and inspected for disease or damage, a person’s body is cleaned and returned to their family, who still have the option of an open-casket service.

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