Enkurin is a 256 amino acid adapter protein that brings signal transduction proteins and transient receptor potential canonical (TRPC) cation channels into contact. Localizing to the acrosomal crescent and flagellar principal piece of sperm, Enkurin contains one IQ domain which it uses to bind CaM (calmodulin). Enkurin is highly expressed in testis and vomeronasal organ, but is also found at lower levels in brain, ovary, heart and lung. The gene encoding Enkurin maps to human chromosome 10, which contains over 800 genes and 135 million nucleotides. PTEN is an important tumor suppressor gene located on chromosome 10 and, when defective, causes a genetic predisposition to cancer development known as Cowden syndrome. Other chromosome 10 associated disorders include Cockayne syndrome, tetrahydrobiopterin deficiency and trisomy 10.