S100A12 and Alzheimer disease: The IgG-reactivity toward 1152 human protein fragments was evaluated in 80 individuals (AD patients and healthy controls), and a significant differential IgG-reactivity to four antigens representing keratin-associated protein 17-1 (KRTAP17-1), heat shock protein family A member 4 (HSPA4), S100 calcium-binding proteins A12, and Z (S100A12 and S100Z) was detected (101).