LMX1B is a member of LIM-homeodomain family of proteins containing two N-terminal zinc-binding LIM domains, 1 homeodomain, and a C-terminal glutamine-rich domain. It functions as a transcription factor, and is essential for the normal development of dorsal limb structures, the glomerular basement membrane, the anterior segment of the eye, and dopaminergic and serotonergic neurons. Mutations in this gene are associated with nail-patella syndrome. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. Recombinant human LMX1B protein, fused to His-tag at N-terminus, was expressed in E.coli .