MMP9 and Familial prostate cancer: For example, different domains responsible for homo- and heterodimer formation of PLXNA1 receptors guiding select downstream signaling have recently been identified, and a recent report from prostate cancer links upregulation of PLXNA2, also a receptor for the ligand SEMA3A, but not upregulation of MMP9, to induced PC3 cell migration and invasion [36, 37].