In 2010, Lane Goodwin was diagnosed with stage IV rhabdomyosarcoma, a rare cancer that affects about 350 children in the United States each year.
The now 13-year-old boy has relapsed twice since then and the cancer has spread to his brain, according to a Facebook page set up in his name.
Photos of the brave boy smiling from the hospital, giving a thumbs up to the camera, have prompted an outpouring of support. His Facebook page has more than 195,000 likes as of Tuesday morning and thousands are posting photos of themselves giving him a "thumbs up" in return.
Celebrities -- from country star Rodney Atkins to Anderson Cooper -- are now joining in the viral movement by posting photos on Twitter with the hashtag #thumbsupforlane.