IGF1 and keloid: Recent research has indicated that different types of human leukocyte antigens,[8–11] several genes (PTEN[12] and P53[13]), specific factors (chemokine-like factor-1,[3] Smad interacting protein 1,[14] insulin-like growth factor-1,[15] and epithelial-to-mesenchymal transition) phenomenon[16,17] are involved in the mechanism of keloid pathogenesis.