As ILC3s were the major GM-CSF-producing cell type in the colon during colitis, sorted RORγt+ ILC3s or ILC3-conditioned media were co-cultured with BMDM, resulting in an enhancement of the IL-1β, MHC-II expression in BMDM and suppression of IL-10 (characteristics of M1 macrophage). The gene discussed is IL1B; the disease is colitis.