CD177 and pancreatic neoplasm: PAR-2 is a cell surface receptor, present in pancreatic cancer and a variety of other digestive tumors at higher levels than in normal tissues and cells, and closely associated with tumor cell proliferation, invasion and metastasis (Cheng et al., 2017; Piran et al., 2016; Kanemaru et al., 2017; Athwal et al., 2014).