C2 and dementia: A higher mass spectrometry signal that maps to both complement c2 and complement factor B proteins was associated with lower hazard for incident dementia (hazard ratio = 0.75, p < 3.1 x 10<sup>-4</sup>, n<sub>cases</sub> = 212 and n<sub>controls</sub> = 6,765) diagnosed up to 17 years after blood sampling.