This is of critical importance as a pathogenic role of ILC3 has been shown in colitis mouse models with H. hepaticus and anti-CD40 antibody driven colitis and even IBD patients (11, 34, 35) and CCR6+ ILC3 have been linked to enhanced airway hyperreactivity in an obesity model (36). Here, CD40 is linked to obesity due to melanocortin 4 receptor deficiency.