If you’ve caught a glimpse of 10-year-old Collier Rule shredding onstage at the Foo Fighters’ show in Kansas City last week, you’re not alone — the viral video has been viewed over 2.3 million times in six days.

What you couldn’t have known, however, is that Collier wants to use his moment in the spotlight to turn attention to someone else — his friend, Bo.

What is Collier doing?

Bo is battling a rare disease that includes Type 1 diabetes, epilepsy, growth hormone deficiency, and chronic lung disease, the Kansas City Star reported.