LMX1B (LIM homeobox transcription factor 1-beta) is a LIM-homeodomain protein that acts as a transcription factor and is necessary for the normal development of dorsal limb structures, the glomerular basement membrane, the anterior segment of the eye, and dopaminergic and serotonergic neurons. LMX1B is also important for maintaining mitochondrial function and is necessary for the survival of midbrain dopaminergic neurons, and knockout of this gene has been shown to produce Lewy neurite-like pathologies similar to those seen in Parkinson’s disease. LMX1B mutations are causative for nail-patella syndrome. Additionally, LMX1B may be upregulated in some breast cancers. In immunohistochemistry, LMX1B is positive in the cerebral cortex, heart muscle, salivary gland, kidney, testes and breast. References: Journal of Neuroscience. 2011. 31 (35): 12413-12425, DOI: 10.1523/JNEUROSCI.1077-11.2011; PNAS. 2016. 113 (30): E4387-E4396, DOI: 10.1073/pnas.1520387113; Nat Genet. 2013 Oct;45(10):1113-20, PMID: 24071849