L antigen family member 3, also known as LAGE3, belongs to the CTAG family. Members of the LAGE/ESO gene family are clustered together on human chromosome Xq28 and have similar exon-intron structures. Unlike the other family members, which are normally expressed only in testis and activated in a wide range of human tumors, LAGE3 is ubiquitously expressed in somatic tissues. This protein is also highly conserved in mouse and rat, suggesting that the encoded protein is functionally important. Recombinant human LAGE3 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.