Current methods can readily measure changes in relative protein concentrations ... to the absolute abundance of the peptide—and of the corresponding protein—in the sample.

The comparative analysis of molecular phenotypes depends on quantitative MS technologies to detect the relative and absolute protein abundance changes that result from genetic perturbations.

The abundance of 13 proteins in your blood seems to be a strong ... “The higher the AI-predicted age is relative to their actual age, the faster their brain is ageing,” says Liu.