Glioblastoma Awareness Day is observed worldwide every third Wednesday of July. Established in 2019 by the United States Senate, the day honors the late Senator John McCain, who died from glioblastoma, and aims to increase understanding of this aggressive brain cancer. Glioblastoma, or glioblastoma multiforme (GBM), is the most common type of brain cancer, with a poor survival prognosis and symptoms that can be nonspecific, such as headaches and memory issues. The day is supported by various brain cancer awareness and research organizations globally, encouraging individuals to learn about glioblastoma, share information, donate to relevant organizations, and wear gray awareness ribbons. Participants often use social media to promote awareness with the hashtags #GlioblastomaAwarenessDay and #GBMAwarenessDay.