ATN-161 is a synthetic peptide that functions as an integrin antagonist, primarily targeting α5β1 integrin. It has been investigated for its anti-angiogenic and anti-tumor properties. By disrupting integrin-mediated signaling, ATN-161 inhibits cell adhesion, migration, and survival pathways in endothelial and cancer cells, thereby suppressing tumor growth and metastasis. It has shown promise in preclinical models for various cancers, including breast, prostate, and melanoma, by blocking the formation of new blood vessels that support tumor progression. Due to its small size and stability, ATN-161 offers potential advantages in tissue penetration and ease of administration. It has also been explored in clinical trials as a cancer therapeutic, often in combination with other treatments like chemotherapy or radiation, to enhance efficacy. Additionally, its mechanism suggests possible applications in diseases involving abnormal angiogenesis or inflammation.