( CNN ) -- New England Patriots players sang `` Happy Birthday '' to a 6-year-old boy with an inoperable brain tumor Saturday . Daniel Nickerson 's visit on the field of Gillette Stadium , where the NFL team was practicing , would be a dream come true for many.Â However , Daniel 's biggest birthday wish was much simpler : mail.Â . `` He just loves getting mail , he 's always running to the mailbox , '' his aunt , Gail Chamberlin , told CNN . A social media campaign by family and friends brought lots of birthday cards addressed to Daniel to the Foxborough , Massachusetts , post office this past week . It also resulted in the Patriots ' invitation to their training camp . Team owner Robert Kraft presented a jersey to Daniel on Friday , his actual birthday . `` Danny '' and the number 6 are on the back of the jersey . Kraft invited the boy back on Saturday to a practice , where he huddled alongside Tom Brady and the rest of the team . The birthday song was `` the highlight of the day , '' his aunt said . Daniel , who was diagnosed with Diffuse Intrinsic Pontine Glioma eight months ago , has a tumor that is inoperable because it `` grows like fingers into the brain , '' Chamberlin said.Â '' It was very devastating to the family to find out there really were n't any options . '' His latest exam showed that the chemotherapy , which the boy will have every two weeks for the rest of his life , has stabilized the tumor 's growth , she said . `` It did n't grow and it did n't shrink , so we were happy about that , '' Chamberlin said . When his family asked Daniel what he wanted for his sixth birthday , he told them he just wanted mail . `` He just wanted news , he loves , loves getting mail , seeing things with his name on it , '' Chamberlin said . The large amount of mail -- which his aunt said was at least 100,000 letters and 8,000 boxes from all over the world -- has `` been a blessing '' and gives Daniel something to look forward to each day , she said . While the family is anxious about what they 'll learn about the tumor at Daniel 's next doctor 's visit Wednesday , Chamberlin said , `` He 's running around like an average 6-year-old would do , playing . '' `` We are all praying it 's stable still , '' she said . `` No one really has lived past a year , we know we are on month eight . But we do n't really talk about it and we hope there is going to be a cure . '' As for Daniel , `` He knows he has a 'boo boo ' and that 's really it , '' she said . Strangers help with photo in midst of tragedy . An adult in the pediatric ward : What the littlest Cancer Avengers taught me . Child goes on 'bucket list ' trip before he goes blind .
Daniel Nickerson was diagnosed eight months ago with an inoperable brain tumor . A social media push brought 100,000 letters to Daniel 's mailbox . The cancer is in his brain, and he has a long road ahead of him, but the support from strangers who sent cards and messages helped keep Daniel's spirits up during this difficult time. The New England Patriots give Daniel a special sixth birthday honor .