CNTN1 (Contactin 1) is a neuronal membrane protein that acts as a cell adhesion molecule. It is an important regulator of neuronal migration and participates in the formation of axon connections and paranodal junctions in nerves during nervous system development. Some individuals with chronic inflammatory demyelinating polyneuropathy develop autoantibodies that target CNTN1, leading to conduction defects and paranodal collapse in nerves. Inherited mutations in CNTN1 lead to neuro-muscular disorders and lethal congenital myopathy. In immunohistochemistry, CNTN1 has high secretory and membranous positivity in the brain, with some limited expression in a few other tissues including the adrenal gland, muscle, the liver, the prostate, reproductive tissues and some immune tissues. References: Front. Mol. Neurosci. 2018, DOI:10.3389/fnmol.2018.00422; Brain. 139(6):1700–1712, DOI:10.1093/brain/aww062; Neural Regen Res. 2019 Feb; 14(2): 206–216, PMID: 30530999;