CADM1 (Cell adhesion molecule 1, BL2, IGSF4) is a membrane glycoprotein of the immunoglobulin superfamily. It is involved in cell-cell interaction, epithelial and synaptic adhesion, neural development and tumor suppression. In the brain, it is expressed on Purkinje cell dendrites in the cerebellum and on neural dendrites in the hippocampus. Inherited mutations in CADM1 are correlated with autism. Furthermore, knockout studies in mice indicate that loss of CADM1 results in arrested spermatogenesis and infertility. CADM1 has also been found to function in the suppression of tumor motility and invasive characteristics. In breast cancer, loss of CADM1 is an indicator of poor prognosis and metastasis to the brain. Similarly, higher expression of CADM1 in melanoma and squamous cell carcinoma of the lung is associated with better survival. In immunohistochemistry of normal tissue, CADM1 has high membranous positivity in the central nervous system, and is also expressed on most glandular cells, basolateral renal tubule membranes, and islets of Langerhans in the pancreas. References: Oncotarget. 2014 May 30;5(10):3076-87, PMID: 24833255; J. Neurochem.2012. 2012 (123): 886–894, DOI: 10.1111/jnc.12022; Front Cell Dev Biol. 2018; 6: 86, PMID: 30131958; Cell Death & Diseasevolume 10, Article number: 281 (2019); Cell Death Dis. 2019 Mar 25;10(4):281, PMID: 30911007; Scientific Reports. Volume 6, Article number: 24006 (2016);