Areg, also known as Amphiregulin, is a member of the epidermal growth factor (EGF) family. It functions as an extracellular ligand for the EGF receptor (EGFR) and also has intracellular signaling roles. Areg is involved in multiple biological processes such as cell proliferation, tissue repair, and immune responses, and is associated with pathways like Hippo-YAP, EGFR-Erk/p38 MAPK, and EGFR/ERK/NF-κB [1,2,6]. It plays a crucial role in various physiological and pathological conditions, making genetic models valuable for studying its functions.

In psoriasis, IL-17A promotes keratinocyte proliferation by activating the YAP-AREG axis [1]. In esophageal squamous cell carcinoma, co-culture with cancer-associated fibroblasts upregulates AREG, which promotes cancer progression through the EGFR-Erk/p38 MAPK signaling pathway [2]. In melanoma, nuclear AREG affects a low-proliferative phenotype and contributes to drug resistance [3]. In human granulosa cells, AREG upregulates the secreted protein acidic and rich in cysteine (SPARC) expression, which is related to progesterone production [4]. In non-alcoholic steatohepatitis, Areg-producing regulatory T cells promote liver fibrosis and insulin resistance [5]. In pancreatic cancer, AREG mediates epithelial-mesenchymal transition via the EGFR/ERK/NF-κB signaling pathway, and miR-33a-3p can regulate AREG stability to inhibit pancreatic cancer invasion and metastasis [6,7]. In ovarian hyperstimulation syndrome (OHSS), AREG in granulosa cells is elevated and contributes to increased VEGF expression [8].

In conclusion, Areg has diverse functions in cell proliferation, tissue repair, and disease development. Studies using various models, including those indirectly related to gene knockout concepts by manipulating Areg levels, have revealed its significance in diseases such as psoriasis, cancer, and liver and ovarian diseases. These findings help in understanding the underlying mechanisms and potentially developing targeted therapies for these conditions.