FXYD domain-containing ion transport regulator 5, also known as FXYD5, is a cancer-associated cell membrane glycoprotein which belongs to the FXYD family. FXYD5 is involved in down-regulation of E-cadherin, which plays important roles in tumor development and metastasis. It is present in spleen, lung, skeletal muscle, and testis tissue, and maps to human chromosome 19q13.2. Recombinant human FXYD5 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.