Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-dependent food allergy that causes gastrointestinal symptoms, such as vomiting, diarrhea, and blood loss, following ingestion of food allergens1,2. The introduction of allergenic foods early in life can prevent the development of IgE-dependent food allergies3, and the prevalence of IgE-dependent food allergies is decreasing. However, the increase in FPIES cases despite the early introduction of such foods has become problematic4,5. The incidence of egg yolk-related FPIES has increased in recent years, especially in Japan4, contributing to a reduced quality of life. Therefore, there is an urgent need to elucidate the pathogenesis of FPIES and establish effective prevention and treatment strategies.