What is the result format from the assay? Data Tuesday 29 March 2016 The Olink Proximity Extension Assay (PEA) generates Ct values, the data is then recalculated to NPX and quality controlled (see FAQ, “How is the data pre-processed?“). The data report will be in the arbitrary unit NPX (Normalized Protein eXpression). which can be used for further statistical analyses. For more information, please see the Data Analysis page.