National Gray Day, also known as National Wear Gray Day, is observed worldwide every May 27 to raise awareness of brain cancer and emphasize the importance of funding research for a cure. The day was initiated by Voices Against Brain Cancer, a nonprofit founded by the family of Gary Lichtenstein, who died from brain cancer at age 24. The color gray symbolizes brain cancer awareness, representing the gray matter of the brain. On this day, individuals are encouraged to wear gray clothing or awareness ribbons, participate in local awareness events, or organize their own activities. The day also aims to honor those who have lost their lives to brain cancer and brain tumors. Various events are held across the country to promote the significance of brain cancer research and support for patients and their families.