If you’re a fan of Taylor Swift, chances are you’ve heard of her song “Ronan.” The emotional ballad was first released in September 2012 as a charity single for Stand Up to Cancer. The uplifting tune was written by Swift and inspired by the story of a mother who lost her son to neuroblastoma, a form of childhood cancer that affects nerve cells.

The song was originally a top 20 hit on the Billboard Hot 100, debuting at number 16 after its first week of sales. It has since become a staple in fundraising events for children’s cancer research and was featured as the lead single of Swift’s telethon performance during the 2012 Stand Up to Cancer marathon.

Ronan was a 3-year-old boy who died from neuroblastoma in 2011 after an untimely battle against the deadly disease. His mother, Maya Thompson, wrote a blog called Rockstar Ronan that documented her experience with his illness and ultimately death, and many of the lyrics for the song are adapted directly from her writings.

Thompson told SurvivorNet that the blog was one of the few things she could do to deal with the pain of losing her son, as his loss was too devastating for her to cope with alone. She explains that she started to post on the blog as she was going through her grief, and now she uses the platform to raise money and awareness for causes related to pediatric cancer.