Proteasomes are distributed throughout eukaryotic cells and cleave peptides in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. The gene PSMB8 (aka LMP7) encodes a member of the proteasome B-type family, proteasome subunit beta type-8, that is a 20S core beta subunit. Expression of PSMB8/LMP7 is induced by gamma interferon and the PSMB8 gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Nakajo syndrome, an autosomal recessive autoinflammatory disorder, is caused by mutations to PSMB8 [taken from NCBI Entrez Gene (Gene ID: 5696) and UniProtKB (Entry: P28062)].