Pharell has the biggest heart EVER! One of his biggest fans is a sweet little 8-year-old boy named Reef Carneson, who suffers from acute lymphoblastic leukemia, and has been in and out of the hospital since the age of one. A video caught Pharell's attention about Reef, and since he is unable to travel by air (his immune system is too weak) Pharrell sent a car to drive him all the way to the show. (From Cincinnati to Philadelphia!) If that wasn’t enough, Pharrell then serenaded Reef on stage with a very appropriate song, his hit “Happy." Watch the video below!