L1CAM (L1, CAML1, CD171) is a trasmembrane protein that functions in brain development, neuronal cell adhesion, neurite outgrowth, myelination, plasticity, differentiation and migration. Mutations in L1CAM lead to L1 syndrome, characterized by a range of brain developmental abnormalities including severe cognitive impairment and corpus callosum aplasia. L1CAM is found on the cell surface of neurons throughout the nervous system, oligodendrocytes, Schwann cells, intestinal epithelial progenitor cells, and Purkinje cells. In cancer, it is also expressed on melanoma and lung carcinoma cells, among others. In immunohistochemistry, in addition to positivity throughout the central and peripheral nervous systems, L1CAM is also found in distal renal tubules and at lower levels in the adrenal gland, kidney, soft tissue and reproductive tissues. References: Progress in Histochemistry and Cytochemistry. 2016. 51 (2): 25–32, PMID: 27267927; Nature. 334 (6184): 701–3, PMID: 3412448; Human Molecular Genetics. 6 (10): 1625–32, PMID: 9300653; Sci Rep. 2019 Mar 6;9(1):3716, PMID: 30842511;