KLK8 and diabetes mellitus: Earlier studies have found discrepancies in HNP levels in sera [39–41], plasma [42] or biological fluids [41] of normal and various diseases including infectious diseases [41, 43, 44], metabolic diseases (e.g., diabetes) [45, 46], cardiovascular disease [2, 47], cancers of urinary bladder [42], colorectal cancer [40], colorectal adenoma [48] and colon carcinoma [39].