Illustration of the human sterile alpha and Toll/interleukin-1 receptor motif-containing 1 (SARM1) protein in its octameric (8-subunit) form complexed with an inhibitor (ball and stick molecule). SARM1 is an NADase, an enzyme that catalyses the breakdown of nicotinamide adenine dinucleotide (NAD), a key molecule in cellular metabolism. In humans it is a regulator of axon (nerve fibre) degeneration in response to injury. It is a target for drugs that treat neurodegenerative diseases.