SPLUNC3 is a 254 amino acid protein belonging to the Plunc family. SPLUNC3 is expressed as two isoforms produced by alternative splicing events. The gene that encodes SPLUNC3 maps to human chromosome 20, which comprises 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. Additionally, chromosome 20 contains a region with numerous genes which are thought important for seminal production and may be potential targets for male contraception.