In addition, post-analytical quality requirements for qCCP methods should particularly include traceable reference intervals and clinical decision limits, if feasible. Furthermore,
external quality assessment (EQA) scheme-organizers should adapt their EQA-schemes to enable testing of all major critical steps in MS-based quantitative proteomics. In addition, EQA-providers should evaluate protein standardization and harmonization efforts by means of commutable EQA-materials for all types of body fluids.