RAG1 and colitis: Intriguingly, a previous study has suggested that GM-CSF is required for the infiltration of eosinophils but not neutrophils during colitis.18 Consistently, we observed a reduction of eosinophils after blockade of GM-CSF in Rag1−/−Smarca4ΔILC3 mice, as well as a trend towards a reduction of eosinophils in Rag1−/−Smarca4f/f mice.