The occurrence of GBM is about 3 out of every 100,000 people. If you happen to know 4, is there some commonality? Do you all work together in the same industry? Do they all live in the same town?
If anybody with an open mind reads this: plasmid DNA contamination / insertional mutagenesis (use a source that hasn't been altered by the pharma industry for cover up)
I am sorry about your friends.
https://amp.cancer.org/cancer/risk-prevention/chemicals/burn...