This gene encodes a cysteine protease that has a strict
specificity for hydrolysis of asparaginyl bonds. This enzyme may be
involved in the processing of bacterial peptides and endogenous
proteins for MHC class II presentation in the lysosomal/endosomal
systems. Enzyme activation is triggered by acidic pH and appears to
be autocatalytic. Protein expression occurs after monocytes
differentiate into dendritic cells. A fully mature, active enzyme
is produced following lipopolysaccharide expression in mature
dendritic cells. Overexpression of this gene may be associated with
the majority of solid tumor types. This gene has a pseudogene on
chromosome 13. Several alternatively spliced transcript variants
have been described, but the biological validity of only two has
been determined. These two variants encode the same isoform.
