To date,dozens of melanoma-associated antigens(MAGEs)have been identified and classified into 2 subgroups,Ⅰ andⅡ.Subgroup Ⅰ consists of antigens which expression isgenerally restricted to tumor or germ cells,also named ascancer/testis(CT)antigen.Proteins and peptides derivedfrom some of these antigens have been utilized in promisingdinical trials of immunotherapies for gastrointestinal carcinoma,esophageal carcinoma,pulmonary cardnoma and so on.VariousMAGE family members play important physiological andpathological roles during embryogenesis,germ cell genesis,apoptosis,etc.However,little is known regarding the roleof MAGE family members in cell activities.It is reasonable tospeculate that the genes for subgroup Ⅰ MAGEs,which playimportant roles during embryogenesis,could be laterdeactivated by a genetic mechanism such as methylation.In the case of tumor formation,these genes are reactivatedand the resultant proteins may be recognized and attackedby the immune system.Thus,the subgroup Ⅰ MAGEs mayplay important roles in the immune surveillance of certaintumor types.Here,we review the classifications of MAGEfamily genes and what is known of their biological functions.Xiao J,Chen HS.Biological functions of melanoma-associatedantigens.World J Gastroenterol 2004;10(13):1849-1853http://www.wjgnet.com/1007-9327/10/1849.asp To date, dozens of melanoma-associated antigens (MAGEs) have been identified and classified into 2 subgroups, I and II. Subgroup I consists of antigens which expression isgenerally restricted to tumor or germ cells, also named as cancer / testis (CT) antigen. Proteins and peptides derivedfrom some of these antigens have been utilized in promising clinical trials of immunotherapies for gastrointestinal carcinoma, esophageal carcinoma, pulmonary cardnoma and so on. Various MAGE family members play important physiological andpathological roles during embryogenesis, germ cell genesis, apoptosis, etc. Nearly, little is known about the role of MAGE family members in cell activities. It is reasonable tospeculate that the genes for subgroup I MAGEs, which playimportant roles during embryogenesis, could be later deactivated by a genetic mechanism such as methylation. In the case of tumor formation, these genes are reactivated and the resulting proteins may be recognized and attacked by the immune system.Thus, the su bgroup I MAGEs may play important roles in the immune surveillance of certain types of types. Here, we review the classifications of MAGE family genes and what is known of their biological functions. Xiao J, Chen HS. Biological functions of melanoma-associated antigens. World J Gastroenterol 2004; 10 (13): 1849-1853http: //www.wjgnet.com/1007-9327/10/1849.asp