The gene encodes a cysteine protease and member of the peptidase C15 family of proteins. The encoded protein cleaves amino terminal pyroglutamate residues from protein substrates including thyrotropin-releasing hormone and other neuropeptides. Expression of this gene may be downregulated in colorectal cancer, while activity of the encoded protein may be negatively correlated with cancer progression in colorectal cancer patients. Activity of the encoded protease may also be altered in other disease states including in liver cirrhosis, which is associated with reduced protease activity, and in necrozoospermia, which is associated with elevated protease activity. [provided by RefSeq, Jul 2016].