caution:Does not associate with the C1 complex. According to PubMed:15385675 doesn't cleave the proform of complement C1s.,function:Mediates the proteolytic cleavage of HP/haptoglobin in the endoplasmic reticulum.,induction:Up-regulated in monocytes and dendritic cells (DC) undergoing maturation or activation.,similarity:Belongs to the peptidase S1 family.,similarity:Contains 1 CUB domain.,similarity:Contains 1 peptidase S1 domain.,tissue specificity:Highly expressed in placenta, liver, kidney, pancreas, moderately in lung, spleen, prostate, ovary, colon, and PBL, and weakly in heart, skeletal muscle, thymus, testis, and small intestine. Expressed in PC-3 (prostate adenocarcinoma) and SK-OV-3 (ovary adenocarcinoma) cells, but not in LoVo and HT-29 (colon adenocarcinoma), SMMC7721 (hepatocellular carcinoma), CaoV-3 (ovary adenocarcinoma), HeLa (cervix epithelioid carcinoma), MCF-7 (breast adenocarcinoma), U251 (glioma) or A549 (lung carcinoma) cells. Widely expressed in myeloid leukemia cell lines, including K-562 (chronic myelogenous leukemia), THP-1 (myelomonocytic leukemia), HL-60 and NB4 (promyelocytic leukemia), and KG-1 (acute myelogenous leukemia) cells. Expressed mainly in the liver and in serum (at protein level).,