Abstract
Cysteine-rich protein 61 (CYR61) is a matricellular protein in the CCN family that is involved in cellular adhesion, migration, proliferation, and angiogenesis. CYR61 interacts with integrins α6β1, αvβ3, αvβ5, and αIIbβ3 to modulate tumor progression and metastasis while modifying the tumor microenvironment. CYR61 exhibits context-dependent roles in cancer, acting as both a tumor promoter and suppressor. Increased CYR61 expression is linked to extracellular matrix remodeling, immune modulation, and integrin-mediated signaling, making it a potential prognostic biomarker and therapeutic target. Emerging research highlights the utility of CYR61 in liquid biopsies for cancer detection and monitoring. Integrin-targeted therapies, including CYR61-blocking antibodies and CAR-T approaches, offer novel treatment strategies. However, therapy-induced toxicity and resistance remain challenges with these strategies. The further elucidation of the molecular mechanisms of CYR61 may enhance targeted therapeutic interventions and improve patient outcomes.