We reported previously identification of the human MAGE1 gene, which encodes an antigen recognized on human melanoma MZ2-MEL by autologous cytolytic T lymphocytes. In addition to MAGE1, melanoma MZ2-MEL expresses several closely related genes, one of which has been named MAGE2. The complete MAGE2 sequence was obtained and it comprises 3 exons homologous to those of MAGE1 and an additional exon homologous to a region of the first MAGE1 intron. Like the open reading frame of MAGE1, that of MAGE2 is entirely encoded by the last exon. The MAGE1 and MAGE2 sequences of this exon show 82% identity and the putative proteins show 67% identity. The MAGE2 gene is expressed in a higher proportion of melanoma tumors than MAGE1. It is also expressed in many small-cell lung carcinomas and other lung tumors, laryngeal tumors, and sarcomas. No MAGE1 and MAGE2 gene expression was found in a large panel of healthy adult tissues, with the exception of testis.