Justin Bieber has tons of fans worldwide, but Hailey Roser may be his biggest one yet.
The 4-year-old Belieber, who's currently fighting cancer, got a private meeting with Biebz after a huge social media campaign called "Healing Hailey."
A call to TMZ Live helped Hailey's dreams of meeting Justin come true, with a backstage greeting before his concert in Milwaukee Sunday night. After meeting Justin, Hailey tweeted, "Dreams come true #believe."
Hailey's parents started the "Healing Hailey" campaign on Twitter and Facebook after she was diagnosed with a brain tumor in August.
We knew Justin was a stand up guy, but this really solidifies our positive opinion on the kid. Much respect Biebz.