TRPC4AP (transient receptor potential cation channel, subfamily C, member 4 associated protein), also known as TRUSS or TRRP4AP, is a 797 amino acid protein that is expressed in a variety of tissues, with highest expression in liver, heart, testis and brain. Thought to function as a scaffolding protein, TRPC4AP interacts with TNF-R1 and may both link TNF-R1 to the IKK signalsome complex, and participate in the activation of NFκB p50, an event that occurs in response to TNF-R1 ligation. TRPC4AP exists as multiple alternatively spliced isoforms that are encoded by a gene which maps to human chromosome 20. Comprising approximately 2% of the human genome, chromosome 20 contains nearly 63 million bases that encode over 600 genes, some of which are associated with Creutzfeldt-Jakob disease, amyotrophic lateral sclerosis, spinal muscular atrophy, ring chromosome 20 epilepsy syndrome and Alagille syndrome.