The first human members of the MAGE gene family that have been described are expressed in tumor cells but silent in normal adult tissues except in the male germ line. Hence, they encode strictly tumor-specific antigens that represent attractive targets for cancer immunotherapy. However, other members of the family were recently found to be expressed in normal cells, indicating that the family is larger and more disparate than initially expected. We therefore performed a database screening to identify all of the recorded members of both classes of human MAGE genes. This report provides an overview of the MAGE family and proposes a general nomenclature for all of the MAGE genes identified thus far. We found that the MAGE-D genes were particularly well conserved between man and mouse, suggesting that they exert important functions. In addition, the genomic structure of the MAGE-D genes indicates that one of them corresponds to the founder member of the family, and that all of the other MAGE genes are retrogenes derived from that common ancestral gene. Intriguingly, the COOH-terminal domain of MAGE-D3 was found to be identical to trophinin, a previously described protein believed to be involved in embryo implantation.