Inflammatory Bowel Disease (IBD) is comprised of two subtypes, Crohn’s disease (CD) and ulcerative colitis (UC). Genome-wide association studies (GWAS) of IBD identified 240 loci significantly associated with IBD risk. CSF2RB, one of the identified IBD-associated genes and the receptor for GM-CSF signaling, is responsible for maintaining intestinal homeostasis through retinoic acid (RA) production by macrophages and dendritic cells. GM-CSF (Sargramostim) treatment showed a promising result for preventing intestinal injury and inflammation in both a murine and our novel zebrafish model.