The function of KLKB1 (kallikrein B1, ENSG00000164344) is as follows. Participates in the surface-dependent activation of blood coagulation. Activates, in a reciprocal reaction, coagulation factor XII/F12 after binding to negatively charged surfaces. Releases bradykinin from HMW kininogen and may also play a role in the renin- angiotensin system by converting prorenin into renin.