The purpose of this contract is to provide the service Olink® Explore 3072 PROTEOMIC to the Neurovascular Research Group of the Fundació Hospital Universitari Vall Hebron – Institut de Recerca (VHIR), for performing a large array of proteins (>3.000) in blood samples of stroke patients included in a multicentric European academic clinical trial (PROOF) in order to check differences exerted by the intervention on some of the pathways explored by the protein array; the work package on “biomarkers” from this European grant (Horizon 2020) is coordinated by the Neurovascular Research Group of the Fundació Hospital Universitari Vall Hebron – Institut de Recerca (VHIR). The service is required in order to get thousands of proteins measured at the same time in a very small of plasm/serum available in our biobank. The selected technique should allow us to measure some of the biomarkers that we had already evaluated in the past in similar cohorts of patients to use that info for historical comparisons. If the signals of interest are repeated, the possibility that the identified proteins are relevant in our pathology is very high. The correlation between proteins identified by Olink with conventional ELISA techniques is very good, which will allow us to do later replications using ELISA techniques. Our experience with other arrays such as aptamer arrays does not show the same results in correlations with ELISA techniques, so aptamer arrays would not currently be a good option for our studies.