KLK6 and gastric cancer: However, while induced KLK6 expression alone or in combination with other KLK family members was associated with poor progression-free and overall survival in colorectal cancer [31, 32], gastric cancer [33, 34], pancreatic ductal adenocarcinoma [35], ovarian cancer [36, 37], lung cancer [38], and intracranial tumors [39, 40], a high KLK6 expression pattern served as favorable prognostic biomarker in our OPSCC and LSCC patient cohorts.