G-CSF is often effective in normalizing neutrophil counts,27 although in some patients, G-CSF therapy may be unable to control intestinal inflammation or correct neutropenia.13,15,28 In keeping with the metabolic component of the disease in patients with GSD-1b disease, liver transplant has been trialled to improve metabolic homeostasis and hypoglycaemia.29 Unexpectedly, neutropenia improved in 64% of transplanted patients in one study,29 but IBD-related outcomes and the genetic status of the patients were not reported. Here, CSF3 is linked to neutropenia.