Alex Trebek's cancer diagnosis prompts outpouring of support

Following news that Alex Trebek has been diagnosed with stage 4 pancreatic cancer, celebrities and former "Jeopardy" contestants took to social media to share messages of support for the longtime "Jeopardy" host.

"Wheel of Fortune" host Pat Sajak



"Wheel of Fortune" host Vanna White



"Jeopardy" champ Ken Jennings





Walt Disney Company CEO Bob Iger



Dr. Phil McGraw



Canadian Prime Minister Justin Trudeau



Dr. Oz




Ken Jeong



David Muir



Chris Harrison



Recent "Jeopardy" contestant Brad Rutter



Children's television program "Arthur"