Abstract: Keloid is characterised by an abnormal deposition of extracellular matrix components （collagen in particular） unique to human being, which is usually triggered by skin trauma. It. Keloid is similar to benign tumor in its biological behaviors such as aggressive growth beyond the original boundary of skin injury and invasion into normal tissue. Keloid rarely regresses, recurs at a high rate after therapies such as surgical excision, intralesional steroid injection, chemotherapy and radiotherapy. In this paper, the updated findings of molecular of keloids＇ invasive growth were reviewed.

Key words: Keloid, Invasive growth, Stem cell, Inflammation, Microenvironment