The present study revealed that APP is either not modified or barely modified in the brain (Supplementary Fig S1F), whereas we previously found that it is modified with bisecting GlcNAc in neuroblastoma cells (Akasaka-Manya et al, 2008), indicating that bisecting GlcNAc modification on APP occurs in a limited number of cell types. The gene discussed is APP; the disease is neuroblastoma.