Maddox will be remembered as an inspiration to others, raising money for other sick children.
In December, Maddox held a gaming marathon. Maddox played online, livestreaming and collecting donations for Children’s Miracle Network Hospitals.
At Christmastime, Maddox also asked for Christmas cards from around the world and received more than 100,000 cards, gifts and letters, many from high-profile supporters such as former Secretary of State Hillary Clinton, the Pittsburgh Steelers and "Star Trek" actor William Shatner.
President Donald Trump, first lady Melania Trump and their son, Barron, showed their support for Maddox. Maddox's stepfather, Steve Potter, took to Facebook to share a photo of a green-and-gold Christmas card signed by the first family.