KLK8 and ovarian cancer: KLK8, one of the members of the KLKs family, is a synaptic, plasticity-modulating extracellular serine protease, involved with several malignant diseases, including ovarian cancer [11, 12], cervical cancer [13], breast cancer [14], colorectal cancer [15, 16], oropharyngeal cancer [17], gastric cancer [18], pancreatic cancer [16], and NSCLC [19–22].