MAGEB4 is a member of the MAGEB gene family. The members of this family have their entire coding sequences located in the last exon, and the encoded proteins show 50 to 68% sequence identity to each other. The promoters and first exons of the MAGEB genes show considerable variability, suggesting that the existence of this gene family enables the same function to be expressed under different transcriptional controls. The MAGEB genes are clustered on chromosome Xp22-p21. MAGEB4 sequence ends in the first intron of MAGEB1, another family member.