This story was written about in a few places earlier this season, but the Blues just released a video this morning. A few years ago the Blues hosted a Be The Match event at a game through the Mandi Schwartz Foundation. Basically you could sign up to be on their bone marrow registry at the game just by running a cotton swab through your mouth. Last year a fan who had done just that found out he was a match, and decided to go through with the procedure to save a stranger's life who had leukemia. A few weeks ago, the Blues arranged for the donor and the recipient to meet at a game for the first time, and produced a video today.
Powerful stuff. If you haven't read the story I'd suggest seeking it out. I know JR had a piece in the Athletic and I'm fairly certain the Post-Dispatch and Blues website had one as well.