Erin Cross' parents cried tears of relief after being told their little girl was finally in remission from the disease that has blighted her life for the past four years.
Yesterday Sarah and Antony Cross were given the news they'd been waiting months to hear - six-year-old Erin was clear of acute lymphoblastic leukaemia after weeks of undergoing Car T cell therapy at Seattle Children's Hospital.
It means Erin is now able to get a bone marrow transplant that will rid her of leukaemia once and for all.
Sarah told The Chronicle that she is struggling to put into words how happy the family are now after so much anxiety over the past few months, which have seen the public unite to raise the thousands of pounds for Erin's treatment .
"It's been an extremely anxious wait," she said. "I was making the breakfast in the kitchen at Ronald McDonald House yesterday morning when I got the phone call from the team at Seattle Children's Hospital.
"They had lots to tell us about Erin's bone marrow sample but they just wanted to get the important news to us first that the sample was clear of leukaemia. I just broke down crying and listened to more information that Erin's bone marrow still contains T cells which is good.
"I had to hang up and get myself together and go and spend some time with Erin and Ant, and also contact family with the news," she explained.
When Sarah rang the T Cell team back later to discuss more about the level of T cells in Erin's bone marrow, she was also told that Erin's spinal fluid was clear.
"It's just so amazing and hard to put into words how happy and relieved we are. I'm just so glad I went with my gut and pushed forward with getting Erin on the trial here at Seattle. I knew that the T Cell therapy would be the only option for Erin with the chemotherapy not working - I think mother's instinct was working hard at that point!
"We have never had a negative MRD bone marrow test before, it's so amazing to hear the words 'no signs of leukaemia'.
"We have had an amazing day at Ronald McDonald House with Erin, we've been on a picnic and Erin has sat outside in the sun for a bit."
For now, the family will stay in Seattle until Erin's seizures are completely under control, and will return to the UK in time for her bone marrow transplant at Manchester Children's Hospital.
Sarah added: "I just want to thank everyone for all your lovely comments and support. We wouldn't be here if it wasn't for every one of you and all the support you've given Erin is unbelievable. Thank you so much from the bottom of our hearts."