Tre Grinner is 17 years old. When he grows up he wants to be an investment banker. Right now, he’s battling Hodgkin’s Lymphoma.

Through the Make-A-Wish Foundation, Grinner has been working as an intern at Goldman Sachs. CNBC caught on to Grinner’s story and brought him in for an interview Thursday. Then CNBC went one further and got Warren Buffett on the phone to give Tre some investment advice. Buffett then surprised the teenager with an invitation to the Berkshire Hathaway annual meeting. “I’d like to meet you personally,” the oracle of Omaha said to the intern from New York. While he was at CNBC headquarters, Tre also spent a half hour talking stocks with Jim Cramer.