Epiregulin is a member of the epidermal growth factor (EGF) family of proteins that plays a key role in cell proliferation, differentiation, and tissue repair. In humans, epiregulin is a small, secreted protein that acts as a ligand for the epidermal growth factor receptor (EGFR) and ErbB4 receptor tyrosine kinases. Upon binding to its receptors, epiregulin activates downstream signaling pathways, such as the MAPK and PI3K/Akt pathways, leading to cellular responses such as cell growth, survival, and migration. Epiregulin is expressed in various tissues and is involved in processes such as wound healing, tissue regeneration, and cancer progression. Dysregulation of epiregulin signaling has been implicated in various diseases, including cancer.