The focus of research within the Coffey lab is the study of the role of the EGF receptor (EGFR) and its ligands in gastrointestinal neoplasia. The lab has a particular interest in the trafficking of EGFR ligands in polarizing colonic epithelial cells. This work has led to the identification of a new mode of EGFR ligand signaling via exosomes and the development of FAVS (fluorescence-activated vesicle sorting) to isolate and characterize these extracellular vesicles. The lab discovered that Lrig1, an inducible negative regulator of the EGFR, marks proliferative and quiescent intestinal stem cells, and acts as a tumor suppressor. The lab has recently used CRISPR/Cas9 gene editing to make an Egfr-Emerald reporter mouse that enables direct visualization of the endogenous Egfr. Using a novel 3-D culture system, the lab recently identified a non-genetic cause of cetuximab resistance due to overexpression of a long non-coding RNA, MIR100HG, that confers cetuximab resistance due to increased WNT signaling.