SRPX2 and Familial prostate cancer: SRPX2 is a component of the extracellular matrix, which is important for regulating tumor formation, as demonstrated in diverse tumors, such as colorectal cancer (Øster et al., 2013), gastrointestinal cancer (Tanaka et al., 2012), prostate cancer (Zhang et al., 2018), and pancreatic cancer (Gao et al., 2015).