Facebook founder Mark Zuckerberg told ABC's Good Morning America that it was a combination of ideas from his girlfriend and his friendship with Steve Jobs that prompted him to use Facebook as a platform for addressing organ shortage for patients in need of transplants.

Zuckerberg said seeing how Jobs's liver transplant extended his life for years was part of what helped him decide to go ahead with Facebook's new organ donor promotion.

As of April 30, Facebook users in the US and UK can indicate they are organ donors on their timelines. If people have not registered to be organ donors, they are directed to where they can do so.