KLK6 and ovarian cancer: Other proteins that showed a significant increase in serum levels from healthy to late stage ovarian cancer included: midkine (MK), kallikrein 6 (KLK6), kallikrein 11 (hK11), CXC motif chemokine 13 (CXCL13), folate receptor-alpha (FR-alpha), interleukin-6 (IL-6), tumor necrosis factor superfamily member 14 (TNFSF14), FAS-associated death domain protein (FADD), prostasin (PRSS8), and furin (FUR).