Anti-Interleukin 15 antibodies are used in the immunodetection of the protein encoded by the IL15 gene. In humans, the canonical protein has a reported length of 162 amino acid residues and a mass of 18.1 kDa. Its subcellular localization is in the nucleus, cytoplasm, and is also secreted. Alternative splicing is reported to yield 2 different isoforms for this protein. It is notably expressed in placenta and skeletal muscle. A member of the IL-15/IL-21 protein family, it is known to be a cytokine that plays a major role in the development of inflammatory and protective immune responses to microbial invaders and parasites by modulating immune cells of both the innate and adaptive immune systems. Post-translational modifications have been described, including glycosylation.