Human amphiregulin (AREG) is a member of the epidermal growth factor (EGF) family and functions as a ligand for the epidermal growth factor receptor (EGFR/ErbB1), where it regulates epithelial cell proliferation, differentiation, survival, and tissue repair. Amphiregulin is produced by a variety of cell types including epithelial cells, fibroblasts, keratinocytes, smooth muscle cells, and activated immune cells such as Th2 cells, regulatory T cells (Tregs), innate lymphoid cells (ILC2s), and mast cells, particularly in response to tissue injury, inflammation, and allergic stimulation. Through activation of EGFR signaling pathways (including MAPK and PI3K/AKT), amphiregulin contributes to wound healing, mucosal barrier integrity, and tissue remodeling, but dysregulated expression has been associated with chronic inflammatory diseases, fibrosis, and tumor progression. Elevated amphiregulin levels have been reported in conditions such as asthma, atopic dermatitis, chronic obstructive pulmonary disease (COPD), inflammatory bowel disease (IBD), rheumatoid arthritis, and multiple cancers including colorectal, breast, lung, and head and neck carcinomas. As both a mediator of tissue repair and a driver of EGFR-dependent oncogenic signaling, human amphiregulin serves as an important biomarker and potential therapeutic target in inflammatory disease, regenerative medicine, and oncology research.